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1999 Brighton Wagon 2.2L auto, 257,000 kms:

 

Just spent 2hrs typing up descripition, then lost it somehow , so I'll be brief.

 

Car runs rough under acceleration, either from a stop ,or trying to pass a car. Ease into it gently and it is fine. Stomp on the gas and it runs rough. CEL is on , has been for years, but the car has run really well up until now. Took it to mechanic, a Subaru fanatic, and we checked the diff. fluids - both are clear and clean and full; same with transmission fluid. Car seems to shift normally.

Put the car on the hoist and I drove it up to 100 kph on the speedo as mechanic looked at the car from various angles. It ran rough when I gave a good dose of gas. The right front wheel seemed to rotate a bit faster than the left front at slow speed

Stored codes off the ECU scan are: P0170, P0304 - cyl 4 missfire, P0440 evap.

Cleared the stored codes and put a new fuel filter on it.

Mechanic suggests that the next step is to change plugs, wires and coil tomorrow.

 

Headed out,drove slowly and easy, even on the hwy, cruised 115 kph easily. Tried to get it to act up by accelerating hard up a hill; car acts up and CEL flashes 5 times then goes out and engine smooths out. 5 minutes later the car acts up, smooths out as I let up on the gas then CEL comes on and stays on.

The car is in really good shape for its age, and I would like to keep it, but this is getting expensive.

Any ideas on WTF is going on?

Thanks.

Yours, Steve

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def change plugs and wires to start with - NGK on both, or NGK plugs (copper cores) & OEM wires - dont use cheap parts store wires, Subarus dont like them.

 

Would not change coil pak just yet - do plugs and wires, clear codes (after reading) and see what comes back (if anything)

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Just arrived home. He did plugs, wires, coil(had to use it as it was ordered yesterday), all Subaru parts,cleared the codes. 1hr. labour. CEL is still out, and car runs well now (knock on wood). Good suggestion on vacuum testing, hopefully the CEL stays off for a while, but we'll look at that later. Thanks for your help.

We had a foot of blowing snow today, people in town had problems getting around, people on the hwy went slow; this old Subaru goes through snow as if it wasn' t even there. I love this car! I call it the Pack Mule - pack it up, point it, and go.

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You guys should be replacing ALL your vacuum lines as well as inspecting the check valve that's attached right ahead of the evap canister, then see if the P0440 comes back. My 95' had what appeared to be 100% original vacuum lines everywhere. A couple, were loosely attached to the nipple, and 2 had splits on the underside that weren't detectable from a visual only. The toughest to reach vacuum line connection is the one under the 2 intake runners on the passenger side intake. If the engine is like mine, you can barely slip a (think it was 10mm) a wrench between the 2 runners, unbolt the vacuum sensor, then carefully work towards rear of engine to remove vacuum lines and replace. I ended up just zip tying the sensor to another spot as it was easier to get at now. Car idled and ran better after doing the vacuum lines, and there are ZERO vacuum leaks. A quick inspection would have had you believe the lines were all OK. My check valve for the evap canister had failed as well. You could blow though it AND suck through it which means it was bad. Cleaning it didn't help either. Now, this was all on a 95' EJ22, and there were ZERO codes getting thrown, but on newer engines they should be more sensitive.

 

Anyways, 20 minutes of vacuum line replacement (if it's rubber, replace it; exception being the power brake canister although those hoses do fail eventually, but make sure the replacement is able to hold the same amount of pressure and doesn't crush easily) with the ones under the 2 runners being most difficult to get at, and the reward was a better running engine, especially at idle which wasn't as erratic after. As well as catching a bad check valve that needs to be working correctly in order to purge fumes from the gas tank, which on newer cars if that feature isn't working correctly, it'll throw evap codes and cause drivability issues. 

 

To 1Subaru1, I suspect your P0440 will come back around 50 miles as those aren't related to spark plugs and plug wires. So do the vacuum lines and check the check valve.

Edited by Bushwick
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A P0440 typically means there's a decent air/vacuum leak somewhere either on the gas tank itself, air leak at the filler tube on the tank, vent tube/hose on the tank filler tube is ripped/broken, or it can be a vacuum leak up front somewhere in the evap vacuum lines or the charcoal canister, gas cap faulty, etc.

 

The evap system is fairly easy to separate visually from the rest of the vacuum lines. The charcoal canister (if like mine) is directly behind the passenger-side headlight, directly to the side of the radiator. It has 2 vacuum lines attached to it, with one of them holding the check valve right by the nipple on the canister. Just follow the vacuum lines as they'll lead directly to the purge solenoid (or whatever Subaru uses), and any other evap-specific sensors, etc. 

 

When I did all my lines recently, I had a real tough time matching the exact diameter Subaru uses, and that was after going to Auto Zone and O'Reilly's. I had to settle on 2 different diameter vacuum hoses. The charcoal canister is a prime example as it has 2 different sized nipples. Some of the metal nipples up on the intake are small, then they attach to a MUCH larger vacuum "T" that seems to act more like a jump-size adapter as the other end goes up in size. You'll see this a lot with all the vacuum sensors on the passenger-side strut tower. The goofy thing is the plastic "T" adapter is actually too large for the smaller vacuum lines, so a little spit is needed to slip it over the plastic "T". All the lines need to be firmly snug and not able to pull off easily. I suggest scoring the old hoses with a pocket knife carefully to avoid breaking the plastic as the old lines will be VERY tight. IF you break a "T" vacuum connector, you can buy a an assortment of them at the auto parts store for like $5. They come in a transparent package. I also strongly suggest doing ONE vacuum line at a time as the sensor directly under the passenger-side intake runners has something like 6 different vacuum lines going to the same area, and if you reverse one, it'll be a headache to diagnose which is wrong. Either way, the engine will thank you as a large enough vacuum leak will lean out the mixture, which can mess with the spark plugs, and over thousands of miles it can hurt the cylinder walls, piston rings, and even the engine. It can also ruin MPG and hurt idle.

 

 

I suspect your possible vacuum leak might be what caused your driveability issues. Replacing the plugs is a temp fix. Any idea what color the old plugs were? If they were white and blistered, that's from running lean.

 

 

 

Read this for a briefing on evap system. It actually mentions the P0440. http://www.agcoauto.com/content/news/p2_articleid/151

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I'll try replacing vacuum lines. replaced filler neck, no more cel for 2 weeks now but still lacks acceleration. Seems to accelerate ok when tank is over 3/4 full. I heard evap test may not run till tank is down to 3/4 full?? Could i still have an evap leak with no cel on?

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