Result from a compression test on a 2.2L

[alia176]

Hey folks,

 

I'm still on the hunt for the famous #1 and #3 cyl misfire code. I started off with running compression test in each cylinder and inspecting the spark plugs. Here're the numbers:

 

cyl 1 - 195 psi

cyl 3 - 195

cyl 2 - 200

cyl 4 - 166 :-\

 

cyl #4 obviously is low on on compression and I'll test it further. At the time, I didn't have anything long enough to throw couple of drops of oil in the cylinder to see if there'd be any effect.

 

The spark plugs are only six months old and they're NGK. They were all gapped to .040" at the time. Here're the gaps now:

cyl 1 - .047"

cyl 3 - .047"

cyl 2 - .045"

cyl 4 - .050"

 

I regapped everything to .040". I'm surprised to see the gaps increased by that much. Also, what's up with the #4 cyl? Low compression means high heat equals gaps to increase?

 

Sometime this week I'll hook up the vacuum gauge to the intake manifold and interpret the readings while under load.

 

I'd like to hear your thoughts on the above numbers. The spark plugs had a white color on one side of the electrodes. Also, couple of them had some surface rust on the metallic area where the socket engages. I assume that some water stayed in the hole after a car wash? I took some pics BTW.

 

I'm trying to figure out if there's blockages in my cats. I'm also chasing a P0420 (catalyst below thresh hold) code. I don't what happened first: bad O2 sensors caused the cats to burn up or bad cats allowing excess fuel to trip the code. My wife did confirm that she smelled burned rubber/wire type smell when the engine started to die on the freeway. Bad cats?

 

I'd hate to install brand new O2 sensors if they're going to go bad soon due to fouled cats. Has anyone installed cats that aren't oem? I mean, have you taken your car to a muffler shop and had them install a set for you? If so, what was the cost?

 

Thanks for any inputs.

 

Ali

'95 Legacy wagon 2.2L

124k miles

automatic, new(ish) plugs, wires, coil pack, knock sensor, clean EGR.

[LosDiosDeVerde86]

did you try running an induction service? I had a lean miss a few weeks ago that was caused by too much carbon build up. Induction fixed that right up.

[f15xxx]

hey, i (think) i had that same code (low bank efficiency), it kept setting the cel, sube replaced both cats under fed emissions warranty, 6 yr 80k miles. parts would have been about $1000.

 

99 leg l sedan, 2.2l 5-sp

[Nug]

I'd leakdown test #4 and figure out where your compression is going before I worried about anything else.

[DerFahrer]

Cylinder #4 is not low, 166psi is a great reading! 1,2, and 3 are actually too high, you probably have carbon buildup, and I'll bet you really have pinging when you get on the gas unless you use high-test.

 

Run some induction as DeVerde suggested. That will bring the other 3 cylinders down a bit, and everything should be even.

[Nug]

Uh, I'm not sure I agree with that. I'd still test #4 and make sure there is no problem.