Cadillac CTS-V - Threw some codes

My 05 with 48k miles threw a p0171 and a p0174 left and right bank lean codes. I reset them and have put about 20 miles on since and they have not came back. Could it be a fuel issue? I run 91 octane. Only mods are cai and exhaust that I know of. I made an appointment to have the fuel filter changed tomorrow. Anyone else have this happen?

Prolly 02 sensors. Can't tell you his many times mine shit out when I owned it.

I would say its less likely that two o2 sensors go bad at the same time than you have some sort of leak in your intake, or dirty MAF sensor.

So it is not fuel system related?

Many people who install CAI's throw lean codes. I did also when I installed a CAI and heads n cam and exhaust. I ended up just turning off the codes.

Its probably CAI related. Make sure there's no leaks in the tubing, and worse case, it may need a tuning. I had this issue when I put on an intake. P0171 and P0174. I went back to stock intake until I can go for a tuning.

So it is not fuel system related?

It could be, but more likely an intake leak or dirty MAF sensor. But, changing your fuel filter is a good thing regardless.

Ok thank you. Is the fuel filter easy to get to or better to pay someone to do it?

I get the same two codes - Randomly at best! I'll go for weeks without issue, then it will happen 3 times in a day.

Thing is, it only happens when the car is really warmed up, and at idle. Never when I'm moving.

My only mod is a Volant, and I figure it has something to do with the CELs.

The car runs and drives perfect.

Fuel filter is really easy to do & to get to. I wouldn't pay someone to do it.

It's on the passenger side frame rail, you'll need a set of fuel line tools (those little round plastic ones) but those are cheap.

actually, you only need 1 size fuel line tool, but they come in a set.

Thanks again. I have the tools but took it in to get it done and have the fuel system looked at. Seems to be running good. I have a couple hundred mile road trip this weekend so I will see.

Fuel filter is really easy to do & to get to. I wouldn't pay someone to do it.

It's on the passenger side frame rail, you'll need a set of fuel line tools (those little round plastic ones) but those are cheap.

actually, you only need 1 size fuel line tool, but they come in a set.

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