I had both P0170 & P0171 so I started with replacing the O2 sensor (as suggested on other sites). After replacing it, the car is running better but the CEL just came back on and the P0170 is still there.

Any thoughts on what I should look at now? Or is there so much that I may as well take it in to the shop?

Thanks in advance.

 

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do you have access to a scanner?
or at least get the info for the LONG TERM FUEL TRIM @ closed loop for the bank that is affected and ill tell you what kind of problem you are looking at.

dont change the o2 sensor.

 

@cruzalekz Thanks for the suggestion. I am realizing now that my cheap scanner is just that...a cheap scanner. All I get are the codes, no additional info.

I'll just take it in to a real mechanic...as at this point I am in over my head.

 

how did you get your cel light off for the p0171???