Please help with a CEL

[user99]

Hi,

First off, thanks for letting me join here and I have enjoyed the information I have gotten from this website already on some problems. Now to the problem.

I have a 99 Toyota Solara SLE V6 with 165k miles and the check engine light is on. Run it to autozone, and they could not give me a proper diagnose so I took it to the local dealer. He said the catalytic converter is bad.

So I go online and find a DEC Direct Replacement catalytic converter, brand new.. $277 (whole catalytic system from manifolds) and put it on there. About a day later, light comes on again. I run back to autozone and there reader says oxygen sensor bank 1 lean, ok.. not knowing which one it is since the car has three of them I bought one.

Put it on last saturday, it was a Bosch 15733 Universal and a day later.. light comes on. Ok, run back to autozone and the reader says the same thing.

So I get another one and put it on the rear manifold last night, drove it for 20 miles or so and no light.. start it up this morning and drive about 10 miles... light COMES BACK ON!

Back to autozone and the reader says the same code "bank one lean, replace oxygen sensor". Now I don't believe its the other sensor since it is behind the catalytic convertors underneath the car.

I call the local dealer that told me the convertor was bad and that I replaced it.. he said that on Toyota's you have to get a Toyota Catalytic convertor system and nothing else.. problem is that it costs $1200.

I have triple checked the wiring on the universal oxygen sensors and it is correct. The car is getting 17.5mpg and I know it has a lot of miles, but it is supposed to get around 22mpg city/highway combined. The car still runs smooth like nothing is wrong, but the CES light is bugging me.. esp since I have replaced everything related to the O2 sensors except the one behind the catalytic system.

I have looked at the MAFS and it looks clean but I do know that they are just little tiny metal things and could just be worn out. I have checked for bad vaccum lines and have not found them. I have ran SEAFOAM through the car (brake booster vaccum) twice and once in the gas tank so I dont think I have clogged injectors and my spark plugs look good.

I did pull the oxygen sensor out of the front bank last night and noticed a little build up on the top of it (it was black and looked like carbon) and I blew that off..

So I really need suggestions here as I have spent $400 on a stinkin CEL. BTW, The car runs great, no stuttering or idle problems. I am seriously thinking it is the universal oxygen sensors, mafs or the ECT but wanted to get an opinion from this forum since its dedicated the the Solara I4 and V6 engines.

Can anyone help ??

[Fratsgotasolara]

b1s1 is the back side (firewall side) top O2 sensor and i would check your exhaust manifold gaskets especially as they were just changed because if its letting ex. out there it would read lean, but it shouldn't be the o2 causeing a lean code anyway. normally intake gaskets or injector sticking closed or maf dirty

[user99]

b1s1 is the back side (firewall side) top O2 sensor and i would check your exhaust manifold gaskets especially as they were just changed because if its letting ex. out there it would read lean, but it shouldn't be the o2 causeing a lean code anyway. normally intake gaskets or injector sticking closed or maf dirty

Thats what I am thinking because the O2 sensor is on the manifold itself and not the exhaust pipe so it should be reading fine even though I may have an exhaust leak... the manifold wasn't cracked when I had it out. I'm thinking its the MAFS causing the injectors to "malfunction" and not give it enough fuel.