iayers

GD, how rapidly can these thing degrade? Is there the possibility of rapid failure? Before I can fix this, I am planning on doing 500mi of holiday highway driving. Can anything be added to the oil or fuel to protect it? How do I know it's BAD??

Nope, runs same cold as hot. Guess it's time for a compression test.

If one valve burns, can this cause other cylinders to misfire, or is it possible that multiple are burning out. The problem has gradually gotten worse over last months.

99 OBW 2.5, 200k I'm getting a very rough idle & rough engine performance at all RPM's. ALL cylinders are misfiring. The car shakes pretty good and CEL flashes at idle. Replaced plugs, wires, and igniter/coil (all OEM, NGK, as recommended). Did not improve whatsoever. The car has been throwing P0420. I ran the car with the O2 sensor unplugged then plugged. No difference in performance. Smells like fuel when running. Been running fuel injector cleaner regularly. Recently Seafoamed the engine through brake booster. There are no exhaust leaks. What should I do next in the line of fixes? Given what I did, what does this sound like? Timing belt? Valves? Cat? Fuel? What would a good Subaru mechanic know to do on this? I will probably need to take it to a guy to check timing, compression, etc. Any help appreciated. Thanks guys. Or, direct to another relevant post?

Guys, thanks for the replies. I ran a can of seafoam through my gas tank, drove the tank empty, then cleared the CEL codes. I've driven 300 miles since the codes were cleared, with no CEL. The guy at Autozone who cleared my code said that an open gas cap can cause P1443. Obviously, I have read the plethora of posts about the gas cap setting off the CEL, but I don't rememebr reading that it caused a P1443 code. The Autozone guy suggested that it did. I doubt that I failed to secure the cap at any point, but whatever. Anyway, maybe the can of seafoam cleared out some thing in the fuel system that was throwing that code. One thing's for sure... the engine feels a lot smoother and I don't smell as much "gas smell" in the exhaust when I first start up the car. All good things. I guess the moral of the story is... seafoam the crap outta yo rig... before you do anything else.

I pulled P1443 out of my 99 OBW man. Also pulled misfire codes out for 3 cylinders. I've pulled misfire codes before, but I never actually feel the misfires when the CEL is flashing. What is the deal with the evaporative emission control system? What is that? Does it suggest an exact part(s) that should be replaced? Is it a cause of misfires, or is it affected by the misfires? My car has new OEM plugs, new OEM wires, I've cleaned the fuel system and the throttle body with seafoam. Any info is appreciated. I'm open to checking stuff with my ohmmeter. Thanks, Ian

Just another thought. You said no obvious oil leaks, but I would make sure to do a thorough check. For example, if you have a bad rear main seal, or some other hard-to-see gasket, she might not notice it, especially if the leak doesn't drip straight onto the ground. My oil separator plate was leaking badly for a while, and it leaked a 2-3 quarts between oil changes- and it leaked onto a hot exhaust pipe and didn't hit the ground. Otherwise, I hope the engine dies close to home, or at least near a good bar.

Wow, so, with all of your help, I resolved the problem, and saved myself a bunch of money. It turns out that the mechanic must have not unplugged the front O2 sensor when he dropped the exhaust out. Richierich hit it on the head. While the mechanic re-plugged in the sensor's wiring harness after doing the job, he didn't realize that he damaged the harness. One of the wires had pulled out of the wiring harness, creating the open heater circuit fault. I just jammed that mofo back in. A simple fix, but all of your posts really made it easy. The mechanic apologized when I told him that I fixed it myself... he offered me a free oil change... but that doesn't add up to the $200 he was certain I needed to pay to get my O2 sensor to work! I think this should have been an obvious fix for a mechanic who's worked with these cars before... Had Advance Auto Parts clear the CEL codes, and I got the car inspected yesterday. Anyway, thanks a lot everyone- I think I oughta donate some $ to this board.

Where is the front O2 sensor? Is it something that I could inspect the wiring if I could get under the car? Is it easy to access/replace the front O2 sensor myself if I bought one? Is there a notable difference in quality among the Subaru OEM model and other brands like Bosch, AC Delco, Walker... ? Thanks to RallyKeith

99 OBW MT, 130k. Just had a local reputable Subaru mechanic replace my clutch, replace a leaking oil seperator plate, cut off the vibrating heat shields, and do the rear main seal. He appears to have done these tasks successfully, but: When I picked up the car from the service, the mechanic said that my Check Engine Light was on, and that I need a new O2 sensor. The CEL was NOT lit before I dropped off the car, 100% for sure. I had Advance Auto pull the OBDII code: P0135, O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1). Here's what I've done based on reading previous posts... Monitored gas mileage for about 500 miles, it is 27 mpg, pretty good. I've unplugged the battery to reset the codes, but the CEL relights as soon as the car is turned on. At highway speeds, sometimes the CEL flashes for a short periods of <10 sec. For you all: What could the mechanic have screwed up? What can I do myself to check for errors? Is there a wiring harness or something I can check for continuity? Could cutting off the heat shields damage some nearby wiring or something? Do these sensors go bad at my mileage? Any insight greatly appreciated... the car is overdue for inspection so I gotta fix this asap.

hi everybody. so, obviously, transmissions wear out over time. my 990bw manual tranny doesn't feel like it did when it's new. (125k on it) but i don't understand what causes it to feel different. for example, lets say I'm in 3rd gear, and i'm driving down a flat road with my foot on the gas. if i quickly take my foot off the gas, the car will sorta lurch forward as it initially starts to slow down. if i were to step on and off the gas, say every other second, the car would be jumping backwards and forwards. when the car is new, if i were to do these same things, the car wouldn't lurch or feel as rough. i don't know if i'm describing this right.... in my mind, i mechanically visualize "play" in the gears, so when i'm stepping off the gas and the torque on the tranny reverses, the lurch i'm feeling is the transition from when the engine is pushing the transmission to when it is slowing the transmission. how do i get the transmission to feel "tight" like when it's new. does the clutch have anything to do with it? might the tranny mounts be loose? what have people typically experienced? thanks.

Here's what I did, and it seems to have corrected the problem as I originally described it. Just did this about a month ago... 1) completely drained transmission fluid 2) replaced with brandy-new transmission fluid works like it did when new now. i figured that before go invasive to try this. glad i did.