Engine check light comes on frequently

I have a toyota corolla 2000, with 60,000 miles on it. Engine check has started to come on frequently for the last two months. I went to the dealer and he said he fixed air vent now eveything should be ok. But two days engine check light is on again, now the dealer says he cant say for sure what is wrong. He says 1) Run cans of BG44k to cleanup fuel injectors ($50) if that doesnt fix 2) Change flat lined 02 sensor ($268) and if that doest work 2) clean injectors and pressure test. All options are expensive and iam looking for soem expert advice.

A flat line O2 sensor?

If this is the case, that’s what’s causing the Check Engine light to come on.

What’s wrong with this tech? He should know that’s the problem.

Tester

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer.

You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code not just their translation into English and post it back here.

  Dealers are no better (or worse) than independent mechanics for almost anything you might need done on your car.  They will almost always charge more per hour and often more for parts and supplies.  They also tend to look at repairs a little different than the independent. 

A dealer may well recommend work that strictly may not be needed, but could be connected to the problem or maybe replace a part when a little repair would fix it ALMOST as good a new.  

There is no need to bring your car to the dealer for any service other than service that is going to be paid for by a recall or original warrantee. 

I suggest that most people would be better off finding a good independent (Not working for a chain) mechanic. In your case the dealer appears to be incompetent.

Actually, it kinda sounds like the dealer’s adviser was trying to save you some money. It’s unclear what that first repair was. If it was thought that something coated the oxygen sensors, rendering them “flat lined” (no voltage output), it may have been further thought that the BG44 might remove the coating, and return the oxygen sensors to functioning. The engine computer can give a first-hand report via the trouble codes. If you bring those code here, we’ve got the decoder, and can advise on the next step.

Drop by a local AutoZone, have them pull any codes, and post them back here for further discussion. AutoZone will do this for you free.

Not trying to be too crude here, but it sounds like you’re try to cheap off and not spend any money at all on this car.
You do not want to replace a dead O2, run a can of BG through it (probably a waste of time), or anything else.
It sounds to me like the dealer is just trying to come up with anything in the world to help since you do not want to spend any money on it.