First, I bought an ebay bosch O2 sensor (BANK 1 SENSOR 1) about two yrs ago, just so u know, i cut the plug on it and one off the old so it fits, Didnt fit with the bosch one. Ran my car on it for two yrs. Now two yrs later I changed it to the one that fits even with plug (NGK) and so i went for emission and I failed. Could it be that i destroyed my cat converter? One mechanic says do a tunes up. What do i need for a tune up? Please advise!!!!
98 GS3 240k km

20 viewed and no responses? What????

is your CEL on?

yes CEL is on and shows faulty O2 Bank1 Sensor 2 in this case just indicates faulty cat maybe, someone said its no use to change it as it just indicates faulty o2 b1s1 or maybe cat. If cat im screwed, Sell car?

You could just buy a new Cat Conv... They are expensive but cheaper than a new car... Have them replace the O2 sensors while they are repalcing the Cat...Just a thought.

^^This is why i love michigan and the no-emission testing

Wow sell the car, for a sensor or cat... you drive a lex. cheap parts dont match the Lexus name.

ok.. for one.. when you get aftermarket oxygen sensors they arent 100% identical to oem ones.. this could cause differences in readings when it comes to the stock computer. now after seeing this plenty of times at the dealership you can get away with changing the oxygen sensors for a time being.. but its sooner than later the cat will go (very common problem) honestly more than likely its the catalytic converters. (mines got the same problem) especially if it has a catalyst in efficiency code.