Dtjapaneshop

Had the cel pop and the only code I'm getting is P0174 with no other codes. Anyone have any experience with this? Where I should start to look? Fuel injector or vacuum line?

pilot4fn

Here's some good info of the same:
http://986forum.com/forums/performan...171-p0174.html

Dtjapaneshop

I actually think it's just the gas cap , I only got that code 1
​​​​​​ time. I've checked it 3 times and says there are no stored codes or anything. Found another thread here and saw ppl saying gas cap and showed the seal all cracked checked mine and it's pretty bad. I have a new one coming on Sunday wish me luck. I appreciate the help!

Dllrd23

gas cap would cause a P044* Evap leak. Did you mean oil cap leak? I read the above thread and my suggestion would be to buy an inexpensive smoke tester. Amazon has them less than 100 bucks. Saves a lot of time. Good luck.

tcora

Apologies for resurrecting an old thread (at least it’s only from last year).

This is a 2003 base 986.

I’ve been seeing intermittent P0174 codes over the last 8 weeks or so. Had one in early August and cleared it. Another one showed up yesterday - although the MIL cleared itself this afternoon, the code was still stored.

Could, I suppose, be a vacuum leak, but I have problems thinking of how there would be one on Bank 2 without also being on Bank 1 (there have never been any P0171 codes thrown). Aside that, it seems logical that, at 195k miles, O2 sensor replacement seems like the prudent path forward.

Any thoughts from the group on the matter?

Thanks.

996love

It’s hard to say without further diagnostics.

Maybe Bank 1 is borderline lean, but hasn’t met the threshold to activate the trouble code.

I would smoke test your engine to see if a vacuum leak exist.

You could also swap the O2 sensors between both banks and see if the issue follows the sensor.

If you can afford it, and the O2 sensors haven’t been replaced in a long time, I would proceed with replacing them both as part of a maintenance strategy.

tcora

Thanks. I ran live data in Durametric and didn’t see anything, as of last night, that seemed dramatically different between banks 1 & 2, across the board WRT O2 data.

As I noted earlier, all 4 O2 sensors have 195k miles on them. I think I’ve gotten my money’s worth out of them. I’m guess I’m wondering if the pre or post cat sensor would be a more likely candidate….