Of course my engine light decides to come on a while back. Just now getting around to getting it fixed. Well the code is p0420. So that's why it hasn't been an urgent fix. But now the light is just getting annoying I've looked through JTIS and other threads and found that it is probably a bad h02 sensor. I have used Lucas injector cleaner in the past, but not in the last 5 months. Could this of been throwing off the sensors? But then again, the code is still coming up, long time after use. Basically, is it more than likely a bad sensor? And is it a fix I could probably do without working on it a week (if so is there a way to see if a sensor is bad and how to replace) or would it be easier to take to shop.

 

P0420 is a catalyst efficiency code and is rarely set by a bad o2 sensor. If you clear the code, how long before it comes back?

 

Let me check. I will clear it tomorrow and then let you know.

 

It also showed one other code. It was p1111. I didn't really understand what it was for when I read up on it in JTIS

 

P1111 means that a full drive cycle has been completed and all emmission tests have passed since the last code clearing. That is why you need to clear the codes now. It may have been thousands of miles ago that the p1111 was set. You want to start from scratch and see if you can either get another p1111 or get your p0420 code to reset.

 

Well I haven't had good luck today with anything. Everything I touch touch today seems to break. Well anyways. Couldn't clear the codes with the reader. Also disconnected negative battery terminal for a few minutes. No luck getting the check engine light to go off. Any ideas?

 

change yuor catalyte sensor underneath near the exhaust