i'll throw my hat into the ring on the side of the o2 sensor as well. i had the same problem in my old c-rx - i had a lot of problems with my old c-rx and this was one of the harder ones to find.


two main things to check for o2 sensor failure are:-
make sure you have no exhaust side leaks (manifold, gasket etc) which would increase the o2 reading therefore causing the computer to go rich to compensate.

make sure the o2 sensor is actually working else you will stay open loop and run rich all the time. if this is the case, there should be a pcm code 15.

if you're interested in testing it there is some good information here:

***o2 sensor information and testing***

good luck.


josh, the o2 sensor is mounterd in the exhaust (manifold or pipe), before the cat. take extreme care in handling if you take it out cos virtually any type of grease or dirt will screw it up....

 

The prior throttle body post was correct. My 97 has this problem now and again too. According to a mechanic I talked to, build-up of crud around the butterfly can cause an air leak past the butterfly and a lean condition at idle. Get a can of throttle body cleaner and an old toothbrush, and have at it. Make sure the butterfly and throttle body are squeeky clean. Note that fuel injector cleaner won't help this problem.

I now routinely do this every time I change the oil.

HTH

Darren

 

My 97 1.5 does this as well. I got a new throttle body today that i custom Ported and Polished and when i went to go switch the two i noticed a huge buildup of black residue on the back of the throttle body and all over the inside of the intake manifold.. I'm guessing it is coming from the vent tube that connects from the valve cover to the intake pipe. So when i finally get an intake i think i might just buy a breather for that..

I have not done a road test yet with my new throttle body on, i'm gonna wait till it stops raining and i'll post what if anything happens later tonight.

 

I performed the throttle body clean up as describerd two
posts ago. It definitely needs periodic cleaning. The car
had a major idle problem as I mentioned in a previous
post in this thread. This was corrected by the dealer
under warranty.

I also noticed what was described in the above post as well,
a build up of black sooty like substance in the manifold
itself. I sprayed alot of cleaner past the throttle body,
but I know it didnt get all of it out.

The car definitely runs smoother, thx for the advice there.

I also noticed that they make two type of cleaners,
one for carb's and the other for throttle body's.
Is there any difference between the two?

Now for the above post, can you/are you going to run
a external breather for that vent tube. Please post
a response to the outcome of this mod......

obx

 

hey OBX, i'm waiting till I get a custom intake made, then i'm gonna get a breather....

 

Clean throttle body, my dad had this problem with 96 LX.
Take intake hose off, spray a lot of throttle body cleaner and use toothbrush to work inside. Wipe all crap with lint free rag. After that you may notice idle go up a lot-then use adjusting screw to reduce it. I believe there's idle speed control valve at throttle body, it can compensate for dirt, but after it gets really clogged car be stalling.
Same applies to 1.8 DOHC-car will stall, after cleaning idle will have to be turned down.
If you can-take TB with idle speed control valve off as one piece.

DO NOT WORK ON HOT ENGINE!
For injector cleaning I recommend Red Line-it's cheaper than "synthetic" cleaners, but difference can be actually felt.

Alex