Catalytic Converter Problems??? - Toyota Nation Forum : Toyota Car and Truck Forums

JasonNoffsinger · 11-05-2008, 03:00 PM

Hi All,

This is my first post. Great Forum. I have been cruising around looking for some answers but can't find anything specific to my problem.

I have a 1990 Celica GT 2.2L with about 140,000 miles. It has multiple issues, but the most pressing right now has to do with the CAT.

One morning a couple of weeks ago, I was pulling away from my house and noticed that I had significantly less power (hesitation, chugging, etc) than when I pulled in the night before. The next day I checked the plugs and wires. There is oil in the plug tubes, but the electrodes seemed fine. I checked the gaps and put the plugs back in (tighter this time they seemed a little loose coming out). I also added some fuel system cleaner. This seemed to help a little bit, but it wasn't back to normal.

I did a little poking around on line and found that the ignition coil could cause this problem, as well as some starting problems that I have been having. I put in a new coil and it made a big difference. Much better power and acceleration (not perfect, but better), also improved the starting issues but did not totally eliminate them.

On Monday night, driving home from work, I had a sudden loss of power. Think 0-60 in about 3 hours. I manged to limp the rest of the way home. When I got back to my garage, I could smell something burning (temp guage had been normal) and popped the hood, there was a lovely orange glow coming from the CAT.

Ahh a plugged CAT! I thought... Last night I pulled it off... and it looks fine. I was expexting to see charred metal or a disfigured lump where the honeycomb should be. Does a plugged CAT look any different than a non-plugged CAT? Once your CAT has glowed that lovely shade of orange, is there any chance that it is ok (assuming the underlying problem has been fixed)? My initial plan had been to knock some holes in the honeycomb, re-install the CAT and do a compression test and sensor cleaning/replacements. But if the CAT is still good, I don't want to go knocking holes in it. What are your thoughts?

Sorry about the long post.

Thanks for your help.

Jason

Doctor J · 11-05-2008, 05:26 PM

Jason, glowing cat is the the sign that it trying to 'burn' the rich mixture. If your celica is non-turbo,
start from reading the trouble codes[even with check engine light is off there should be stored some.

jlspec · 11-06-2008, 02:01 AM

Oil in the plug tubes mean you need to change the valve cover gasket along with the ones around the spark plug holes. You might as well do a complete tune up.

JasonNoffsinger · 11-06-2008, 09:42 AM

I checked for error codes last night, but came up empty. Just a flashing check engine light, no pauses. FYI-I have not unhooked the battery since "the event". I think I will try re-installing the CAT and doing some more diagnostics.

jlspec, could the oil in the tubes be leading to the overheating CAT? A complete tune-up may be beyond my meager mechanical abilities.

I was going to clean my MAF sensor, but couldn't find it??? My haynes manual shows it sitting on the air cleaner box, but mine is just a simple plastic box with the small temperature sensor. Am I missing something?

Any other suggestions for diagnostics to run???

Thanks for the responses.

Jason

concealer404 · 11-06-2008, 11:10 AM

Quote:

Originally Posted by JasonNoffsinger

I checked for error codes last night, but came up empty. Just a flashing check engine light, no pauses. FYI-I have not unhooked the battery since "the event". I think I will try re-installing the CAT and doing some more diagnostics.

jlspec, could the oil in the tubes be leading to the overheating CAT? A complete tune-up may be beyond my meager mechanical abilities.

I was going to clean my MAF sensor, but couldn't find it??? My haynes manual shows it sitting on the air cleaner box, but mine is just a simple plastic box with the small temperature sensor. Am I missing something?

Any other suggestions for diagnostics to run???

Thanks for the responses.

Jason

You don't have a MAF. So at least that's one thing you don't have to do.

If all cylinders are firing, the oil in the tubes won't cause this.

In all honesty... it does sound like a clogged cat. I wish i could help more... but i don't have a cat on my car.

jlspec · 11-06-2008, 12:29 PM

A tune up is pretty easy. Change the gasket I mention to clean up that oil leak into your sparkplugs. At the same time buy your self some new NGK copper plugs and new OEM toyota wires. Check you timming (very easy job all that you need is a light gun). Change your oil and filter along with your fuel filter. Make sure all belts are in good shape and check for any other oil leakage. Also get yourself some fuel cleaner and use it with each full tank to try and clean up your injectors. As for your cat, you could always trying finding a buddy with either a camry or MR2 none turbo and swap out the cat and see if it helps. If that solves your issue then you'll need a new cat.

JasonNoffsinger · 11-21-2008, 01:35 AM

Sorry it took so long to follow up on this...

I did some more checking and found that cylinders 2 & 3 were both dead (don't ask me how I missed this in the beginning). Compression test showed 160psi across the board. I was getting good blue spark from all the plug wires and I checked the ignition timing (thanks for the suggestion jlspec) and made a slight adjustment, but it did not really effect performance at all. While doing all of these tests, I noticed a strong smell of gas from the exhaust (gas in the exhaust = bright orange CAT). Being out of ideas, I decided to take it to the shop.

Their initial diagnosis was fuel injectors "dribbling" fuel into the cylinder (rather than spraying). No spray, no ignition. They got the injectors pulled (no small task) and bench tested them - perfect working order! Back to square one, but luckily they did not charge me for all the labor to get to the injectors. Finally, they figured out that the oil leaking into the spark plug tubes was causing the plug wires to arc, so no spark from the plugs in cylinders 2 & 3.

So the final solution was - new valve cover gasket, new spark plug tube gaskets, and new plug wires.

Got the car back on Tuesday night and it is running better than it has since the 90's

.

I am getting a strong odor of gas from the engine compartment (not the exhaust), so I'm thinking they may not have gotten everything buttoned up tight after checking the injectors. I will take it back in tomorrow and have them check. If anything else pops up, I will report back.

Thanks to all for the help on this.

Jason

jlspec · 11-21-2008, 06:44 PM

Exactly, the oil in the spark plug was causing the spark to not make perfect contact with the wires which will cause an excess of fuel not being burn causing the red glow. As for the fuel smell, that might because of the work done to it, but do check to make sure the bolts are tighten down and the injectors are not strip and that they are tight.