So I bought a 07 Acura TL and there was no check engine light but I drove it about 100 miles and it came on. I took it to autozone they gave me the code I took it to a mechanic and he changed it. So it turned off for about 150miles and turned back on. Now it turns off until I go over 80mph or 4,00rpm then the next day it turns off. Before I put more money into it does anyone have any Ideas? I checked the spark plugs and theyre worn out idk if that has anything to do with it. Please help

 

In theory if the downstream sensor is throwing a code, there are three options.

1.) Downstream sensor has gone bad, replace
2.) Upstream sensor has gone bad, replace
3.) Cat has gone bad, replace

How do you know the plugs are worn out? How many miles on it?

 

Well I took one out and theyre old and rusty. It lools like the previous owner didnt take much care of the car. The oil was dirty so was the air filter. Im idling rough or misfiring so I havent changed them. The code I got from autozone was
Code P0157 Front Secondary HO2S (BANK2, SENSOR2) Circut low voltage

 

*im not idling rough or misfiring*

 

Yup sounds like you should replace the o2 sensor now. Don't go Bosch, whatever you do.

 

What im thinking is the mechanic installed a used one or a cheap ass one. See this is why I like to do things myself but when youre far from home and your tools this is what happens. Can anyone tell me the location of S2 B2?

 

Very likely..

https://acurazine.com/forums/third-g...erence-973370/

 

Thanks A lot you guys I really appreciate the help I really do. I got this as a project car so I knew it needed work... but ive never owned japanese cars. SO THANK YOU!

 

Denso or NTK. End of story. Check rockauto.
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I agree with the others. I tried to replace my upstream O2 sensor with an aftermarket/alternate brand once...first was actually faulty, other one crapped out shortly after my DMV inspection. Replaced both with denso and it's been perfect ever since. If you generally do your own work, the O2 sensors are pretty easy to change yourself and will save yourself a couple hundred bucks. It's just a bit of learning how the clips work with the B1S1 sensor if you have to mess with that one, given that it's hard to see (because of the faulty parts, I've changed the damn thing 4 times now so I am pretty quick with it at this point!).