Check Engine light driving me insane

[Mickyblue]

I have a 96 camry with 197k miles on it, recently replaced the O2 sensors... i was told my car was cali spec, but under the hood it says its Federal only, and yet for some reason, i have 2 catalytic converters, one on the manifold and the one underneath... well long story short i was told by toyota the engine light is saying the Cat was bad, and the O2 sensors were bad. Well after that me and a friend took the manifold appart and found out why the car was running slow, the cat was clogged. So we ripped it out, now it runs better.

But i have the O2 sensors replaced, and i still have this engine warning, car runs the same... basically my gas mileage is 29mpg on highway when it should be 31 or 32. AND I CANT FIX IT! it still says bcuz of the cat...

So i was thinking, what can i do to make the car run better? have the ECU reprogrammed? or buy a computer from a camry that only has the one catalytic converter? or would that be a problem because it may come from a 95 camry and i have a 96... is there any real difference?

Ideas appreciated before i drop my money on a guy to reprogram only to find out he sucked and didnt do anything

[Hajoca]

2 cats then it is a Cali spec car.

[91MR2quickNA]

96+ 5SFEs are OBDII compliant, so you can't use an older ECU because your car is already wired for OBDII. Cat efficiency is determined by the upstream O2 sensor (before the main cat) and the downstream O2 sensor (after the main cat). The secondary cat is a passive catalytic converter, and doesn't do much on CA spec cars. The main cat on the exhaust manifold is the one that matters, and that's the one you removed, so it's no wonder you're throwing a cat efficiency code.

[toyomoho]

What was the exact trouble code(s).

[Mickyblue]

no no... my cat was plugged because it was old with 190k original miles on it and was making the car run like crap. toyota told me it was both the cats and the O2 sensors... so when i bought headers for like 20$ on ebay, thinking hey, a celica gt has the same engine, i didnt realize that an engine mount was in the way.. So we took the cat appart and was shocked... so my friend drilled it out... now the car runs better than before, like more power, but still fuel mileage is a lil off and the engine warning light is on

[Mickyblue]

Ok, so now i get what OBD2 means... i was looking around on ebay and they sell OBD2 scanners that can erase the engine check light etc etc....

but the other day one of my headlights went out, so i took my battery off, installed the bulb, and decided to clean some battery acid... well after putting the battery back in my check engine light dissapeared. and for some weird reason my car runs like it has more power... did i reset the computer?

[toyomoho]

Yes

[91MR2quickNA]

Originally Posted by Mickyblue

no no... my cat was plugged because it was old with 190k original miles on it and was making the car run like crap. toyota told me it was both the cats and the O2 sensors... so when i bought headers for like 20$ on ebay, thinking hey, a celica gt has the same engine, i didnt realize that an engine mount was in the way.. So we took the cat appart and was shocked... so my friend drilled it out... now the car runs better than before, like more power, but still fuel mileage is a lil off and the engine warning light is on

So is there an unclogged main cat in place or not?

[Mickyblue]

Its gone, the main manifold cat is removed, so the exhaust comes out freely into the exhaust pipes.

[prnc_chrmng]

^ then thats probly why its throwing another CEL. because your missing one cat. and the second o2 sensor is getting a bad reading. buy a new main cat at $400-500 and your problem should go away

[Mickyblue]

..... my check engine light has been that way for atleast a year now... i diid the removal of the big cat like 2 months ago... and ive had it retested and they said the same thing they did before when the cat was there.

you know how much a 96 camry cali spec manifold costs? $1200

[Kep]

From what I read you have modified your exhaust system. Whether or not the car runs "better" will not persuade the computer to turn off an error code. If it is expecting a particular reading from an O2 sensor and doesn't get it it will throw a code. You can't negotiate with it. The O2 sensor is going to throw an error code if the cat is bad or if the cat is missing. It will only be happy if the cat is installed and operating correctly.

If you want to get rid of the CEL code you will need to bring the car back within specs. This will require good O2 sensors and the appropriate catalytic converters. I'm not positive but I believe that you can use aftermarket "generic" cats if you want to get one cheaper. However, do some research to verify this before you go to the trouble. Also, if you had to drill out one cat because it was so clogged up then I would suspect that the remaining cat may be bad also.

What model is your Camry? What code(s) is it throwing?

Kep

[prnc_chrmng]

Originally Posted by Mickyblue

..... my check engine light has been that way for atleast a year now... i diid the removal of the big cat like 2 months ago... and ive had it retested and they said the same thing they did before when the cat was there.

you know how much a 96 camry cali spec manifold costs? $1200

sure, it may have just been an o2 sensor a year ago. but after removing the cat, changing the sensor wont do a damn thing. you can buy jus the cat on the maniforld for around $500

[91MR2quickNA]

If you want to keep that main cat off, I suggest you invest in Federal spec 1996 Camry ECU.

[ShawnM]

Am I missing something here? You dont want to replace the main cat but your willing to spend all kind of money to turn the check engine light off? An ECM out of a 96 federal spec camry is still an OBDII system and will still cause a check engine light. Theres no mystery here, replace the main cat and your done.