Fairtax4me

http://opposedforces.com/parts/

I know several people who have had this type of problem with brakes. It generally tends to start happening about 6 months to a year after pad replacement. I've never been able to definitively pint this problem down, but I believe it has to do with the way the rotors wear. The pad doesn't usually cover the entire machined surface of the rotor, there will usually be about 1/8th inch of room on either side of the pad where the rotor doesn't wear at all. The area under the pad wears down, leaving a ridge on either side of it. This ridge, since it never gets cleaned off by the pad, also rusts badly, and eventually starts to wear the inner and outer edges (in relation to the hub) of the pads. This traps heat in the pads, and makes them "chatter" as the car comes to a stop. It usually gets worse as the brakes get hot. It also seems to be worse if you use cheap pads. When you look at the rotors, if there is a ridge around the outer edge, take them to a machine shop and have them turned. Or just replace them if you want, but generally it's 10 - 15 bucks each to have a rotor turned and new rotors cost $30 or more a piece.

I'll second the AC compressor problem. It's possible the compressor is locked up. But I think the plug you are pointing to is for the rotation sensor on the compressor. You can turn the compressor by hand. With the engine off grab the hub on the very front of the compressor (with the 3 bars crossing it) and spin it with your hand. It should spin easily. If it is difficult to move or doesn't move at all then it's damaged internally or the bearings are locked up. You could be having more alternator trouble, or it could be poor connections due to corrosion. There could also be corrosion inside the cables (under the insulation) which will impede the flow of electricity. The plug in the second picture I'm not sure about. But are you sure you really want to plug it in? Just kidding. There is bound to be a link on the board here somewhere for a service manual for your car. You can look at the wire harness connector location diagram and find out what 4 plug connectors there are in that area and what they're for.

No. The spring just holds the stick in the center position of it's travel. It's just enough resistance on the stick to keep it from flopping all over the place while cornering, and it also helps make it a bit easier to find 3rd and 4th gear when shifting. It has no effect on the internals of the transmission. When you are driving around, do you ever rest your hand on the shift lever? A lot of people have e tendency to do this, and while it seems harmless, it actually causes the shift forks to wear because they are constantly under pressure. It's not a lot, but it is just enough to make the bushings on the fork contact the synchro hub and wear them down. This will eventually prevent the hub from fully engaging, causing the "gear" to pop out when it is put under load. Bet you can't guess which gear this happens with the most often?

On the contrary, R134 can and does quite often "just disappear". Or at least that's how it would seem. R134a molecules are so small that they can actually escape the system through the gaps in the molecular structure of the rubber hoses. This is especially true on R12 systems that have been retro fit for R134. Newer hoses are different material which makes it harder for the refrigerant to escape, but not impossible. but if you looked at a rubber hose on a molecular level it's such a maze it would be similar to a person trying to hike 1000 miles through a rain forest jungle. So the refrigerant disappears very slowly, on the order of about 7 - 10 years for R134 systems. But older R12 systems that have been retro fitted the refrigerant can escape in 1-3 years. Now the chances of an O ring failing, or some other component or seal failing in that time are fairly high. Most AC systems end up having to have some sort of work done in the first few years of service. People often have to recharge the system long before enough refrigerant has "seeped out" to notice the difference. I've used the DIY kits before but never the kind with the cheesy pressure gauge. Recharged the system in my mothers 98 Camry with one of those most recently, and have done it several times to friend's cars with good success. They probably don't make the system work 100% as well as it did when it was new, but on a 13 year old (or older) car who the hell really cares? If someone manages to overcharge the system, and it still isn't working properly, then there is another reason the system isn't working.

Does the Check engine light work? Is it lit?

Are you driving it with the crank pulley still wobbling around? Or did you re-tighten it and I just read wrong?

Generally the last 8 digits or so of the VIN are scribed or stamped on the engine somewhere. Some car makers put the whole thing, some just the assembly number at the end. Always seems to be very hard to read though. I remember seeing a section in the FSM for my 96 that showed where the VIN stamp is. I don't recall exactly where but it was on the bell housing i'm pretty sure.

Here are a few other tricks about the P0420 code. P0420 is Catalyst efficiency below threshold. But what determines the catalyst's "efficiency"? Well the cars Electronic/Engine Control Module (ECU) receives a signal from two oxygen sensors (or more depending on the vehicle), one before and one after the catalytic converter(s). It compares the values of these two signals and based on a preset graph determines if they are within a certain specified range. If the values of these signals falls outside the acceptable range, the ECU determines that there must be a problem with the catalyst, stores a code, and illuminates the MIL. (malfunction indicator lamp, aka check engine light) What is the problem with the catalyst? Usually it's clogged and can no longer fully process the amount of exhaust gas entering the catalytic converter. There can be several reasons for this. Usually because the converter is old and is just "used up". But it may have been damaged by driving while the engine was misfiring, allowing raw fuel into the cat will cause it to overheat and melt. It could be oil contaminated due to piston ring damage, worn valve stem seals, or worn Turbo bearings/seals allowing oil into the exhaust stream. Driving with a bad O2 sensor can also ruin the converter much the same way as driving with a misfire. The cure here is to replace the damaged or old converter with a new one, which you have done, yet it has not cured the perceived problem that is being detected by the ECU. So why has it not cured the problem? Well probably because the converter wasn't the problem in the first place. A new after market converter has to stand up to the same "cleaning" standards as a new OE converter, otherwise the EPA won't allow it to be sold. So ,for a short time at least, the after market converter should do just as or nearly as good a job of converting harmful exhaust gases into less harmful forms as the original unit. The difference is in how long the converter lasts. An after market unit is designed to last maybe 3 - 5 years, whereas the OEM unit has to last at least 8 years. The EPA warrants catalytic converters supplied on new vehicles for 8 years or 80,000 miles. So it is to the manufacturers advantage to use high quality components that will last at least that long or in many cases longer. Especially in the case of certain manufacturers who offer 100k mile warranty periods on their new or certified used vehicles. If it's not the converters fault what is it? Just because the ECU finds a problem, doesn't mean it always finds it in the right place. There are plenty of cases where this code has been set because of a failing O2 sensor, either upstream or downstream. (which you've replaced both of) Or because of another problem that the ECU hasn't yet detected. The EGR valve for example, one that is partially stuck open when it is supposed to be closed, yet still moves freely when the ECU tells it to. The ECU may not be able to detect the problem, but it presents an opportunity for air to leak into the exhaust stream which can effect the signal of the upstream O2 sensor just enough that it reads a lean condition. This tells the ECU to add more fuel to the mixture to prevent combustion temperatures from getting too high. This can also be caused by exhaust leaks before the upstream O2 sensor, usually at the cylinder head or at the weld where the pipes come together. It could also be a pinhole behind a heat shield that is not visible, and can't yet be heard. Or it may be a leak right around the O2 sensor itself. Problems can also be caused by vacuum leaks. If there is a leak between the manifold and cylinder head next to just one of the intake ports the mixture for just that cylinder can be throw off. The ECU has no way to detect, nor correct this unless it gets so bad that a misfire occurs. But before it gets to that point the O2 sensor will start to read that the mixture is lean. The ECU will detect changes in the mixture between cylinders at low RPM when the exhaust is moving fairly slowly. But it generally sees this rich lean rich lean back and forth "swinging" as normal operation because no two cylinders burn the mixture exactly the same. At some point it will read that there is a problem with the mixture and will start to richen to correct the lean part of these "swings". But the problem is, now the downstream O2 sensor starts seeing a lower oxygen content due to the extra fuel being added to correct the swing. Rather than blame itself (for a reason it can't detect), the ECU determines that the catalytic converter must not be doing it's job, and it sets a code... P0420. Meanwhile there is nothing wrong with the catalyst, or the O2 sensors, it's just an air leak confusing the computer.

All of the bolts on the rear bushing for the control arm are ungodly tight for some reason. Makes no sense because the manual says they should be torqued to something like 65ft lbs. I guess because they aren't generally a part that gets removed, they seize up, but the best way is with a big impact wrench. If you don't have one, constant pressure applied with a breaker bar and cheater pipe and have a friend or helper whack the bar down near the bolt with a BFH.

The O2 sensors sole responsibility is monitoring burned exhaust gases and reporting the oxygen content of those gases to the ECU so that it can adjust the A/F mixture accordingly. There are a lot of factors that go into how much fuel is consumed, air density, air temperature, throttle position, engine RPM, engine temp., and so on. The O2 sensor is more for fine tuning the mixture to give optimal fuel economy for the conditions, and helps to maintain proper combustion temperature which helps keep down harmful emissions creation. The O2 sensor doesn't work until it reaches about 600°F. This is why the upstream sensor is usually located very close to the engine, usually right at the point where the exhaust pipes from each bank of the engine (or each cylinder on a inline) come together. Most V engine cars use a sensor for each bank. Modern sensors have heaters built in to help get them up to operating temperature faster. Other than that temperature has no effect on the sensor. It does not measure exhaust temperature in any way. However, it can be used to calculate exhaust temperature range, based on the output signal created by the sensor. Given that the sensor in in proper working order, and the fuel mixture is "normal" If the sensor sees more oxygen, the mixture is lean, which indicates a higher temperature. If you've ever blown on a fire, it gets hotter. Same principle applies to internal combustion. More air = more heat. If it sees less oxygen the mixture is rich, which makes a cooler burn, thereby lowering exhaust temperature. The ECU starts using data from the O2 sensor as soon as it is available(after the sensor warms up). Generally within a minute or two of starting the engine. It will begin adjusting fuel mixture as soon as it gets a reading from the sensor. But the optimal (most efficient) AF ratio will not be achieved until the engine coolant has reached operating temperature.

As already described the knock sensor is on top of the engine block tucked away under the air box. It's easy to see and change, but the question is, is yours bad? It's hard to tell without being able to see what is going on with the engines ignition system while it is running. This means having the car hooked up to a computer and streaming info in realtime from the ECU to look for abnormalities. Generally if the knock sensor goes bad, the ECU sets a code. What does it do? The knock sensor senses knocks. It picks up the ringing sound created in the engine when detonation (spark knock) occurs. Repeated detonation can be detrimental to the health of the engine, and also increases harmful emissions into the atmosphere (mostly NO2 gas). When it hears spark knock occuring, it tells the ECU to retard (dial back) the ignition timing advance in an attempt to correct the situation that may be causing the knock. This creates a drop in power, but generally doesn't cause the car to "fall flat on it's face" as if it has lost all power. It will usually only last for a few seconds then return to normal, if you notice any power loss at all. A bad knock sensor can cause the type of problem you are having, but so can a ton of other things. I think the dealer fed you a load of bull with the fuel tank air valve thing. It may be common for them to go bad but a slight amount of vacuum in the fuel tank will not cause any noticeable drop in fuel pressure going to the engine. The fuel pump is capable of upwards of 50psi. You would need to have about 30 inches of vacuum in the fuel tank to cause any drive ability problems, and the fuel tank just isn't sealed well enough to hold THAT much vacuum. The valve may very well have been faulty and needed replacement, but I just don't see any way that it would be causing the problem you are experiencing.

Well I tried for ya, but he said MD was just a little too far to go. His truck apparently only gets about 10mpg (old truck) which would make his fuel cost just to get the car about $150, possibly more, at current prices. I did tell him it was drive able, but with the loose crank pulley, probably not ~175 mile trip worthy. To be honest if I had the money right now I'd take it off your hands. I keep finding these things in decent shape for low $$$ that would make perfect flippers if I only had the budget. Put it on the DC craigslist I'm sure you can find someone to give you some cash for it.

Knock sensor is easy to replace but usually sets a code. The TPS is a bit more involved but only because you need to adjust it so the ECU gets the proper reading from the sensor at 0 throttle. You could keep throwing parts at it, or do some real diagnostic work and fix the problem without spending a jathousand dollars. I don't know of any sensor that controls air flow to the fuel tank. Find your service receipt and post exactly what part or parts they replaced along with any other info they might have put in the description.

I'll let him know about it. He's a co-worker who flips cars like this on a pretty regular basis. (fix and sell) Price range sounds good, I would think somewhere around 750 - 1,000 depending on body condition. Any major body damage? Looks like a bit of ripple on the left front fender, and maybe the rear quarter? I don't see any rust, but I can't see underneath. How about interior? Any cracks in the dash, rips in the seats or carpet? What shape are the tires in? Brakes? Axle boots ok? Any problems with the transmission? (torque bind) More than likely he would just trailer it back, but being driveable is certainly a plus. I'll ask him about it and let you know something tomorrow evening.

That McIntosh unit could bring some money on Ebay. Kinda hard to believe but there are people out there willing to pay hundreds for those things.

I may know someone who might want to buy it off you as is. Where are you in MD and how much would you want for it?

While I agree, the problem with that is some people would put the full size spare on, and leave it. They would never get the flat tire fixed, or replaced, and would end up with another flat in a few weeks or months or years, and be SOL because they don't have a good spare tire to put on the car. Car companies often purposefully make spare wheels ugly, so you won't forget to get it fixed.

Not easy to reset? Or it doesn't have either?

Is the car running OK? Check the green test mode connectors under the dash first. They should be disconnected. If you find them apart the get the car to a local parts store and have the code scanned then post it here.

Might be a knock sensor problem, throttle position sensor, or my favorite... a vacuum leak. Or any number of other things, but knowing the actual code that is being set when the CEL comes on will hep. Even if the light turns off it still stores the code and can usually be read even after the light is off. It might help to get the freeze frame data that the ECU records when the code is set. You'll need access to a fairly high end scanner to get this info.

If it is the Check Engine light, then no, that light is mostly reserved for emissions related diagnostics. If it is a Maintenance Required light, or Service Soon light then yes that's probably a timed light which can usually be reset pretty easy. More than likely it is the CEL and its an Evap system or EGR related code. Or maybe even a MAP sensor code if it occurred within the first 30 miles or so, or 15 - 20 minutes after resuming driving after a pit stop. Take it to your local parts store and they should be happy to scan the car for free and read the code. Write it down and post it here and we can tell you if it's serious. It's probably not since you say the car still ran just fine.

So does the noise increase in frequency as the car increases speed? Does your car have plastic wheel covers? I noticed since it has gotten warm (riding with the windows down) that my car makes a weird almost quacking sound when driving. It's there at all speeds as far as I can tell. Hard to say above about 45 because the noise of the road and engine drowns it out. I had a friend listen while I was driving the car across the parking lot and he deducted that it was coming from the wheel covers. Sure enough, popped them off and the noise went away. Put them back on, there it was again. Kinda strange, but might be worth checking. On a 2002 though, you probably have aluminum wheels. Brakes can squeak multiple times per revolution even if the rotors are in perfect shape. All it needs is a spot just ever so slightly higher than the rest to rub against the pad to make a noise. It's usually worse if the pads are down to the squeal clips (wear indicators).

Use a manifold gauge to read system pressures, trying to check it by tricking the compressor into turning on tells you nothing. There are several relays for the AC system IIRC. I don't remember of hand exactly what each one does, but you may be able to find out by searching the boards here for an online copy of the service manual for your car. Where was the switch that you jumped? The pressure switch is mounted on top of the accumulator/drier on the passenger strut tower. Be sure to check any fuses related to the AC system in the main fuse/relay panel.

Do you leave the headlight switch in the On position when you turn the car off?