dtc code 171 and 174?
This is a discussion on dtc code 171 and 174? within the Computer & Tuning forums, part of the LSx Technical Help Section category; im popping two codes on my 04 A4 gto, #171 and #174, bank 1 and 2 system too lean. I ...
07-14-2008, 08:33 AM #1
dtc code 171 and 174?
im popping two codes on my 04 A4 gto, #171 and #174, bank 1 and 2 system too lean.
I have long tube headers, and dual 3" exhaust running through flowmaster super 44's, cai, SLP maf, p&p throttle body, and hp tuners program.
what would cause this and where would i go in the hp program to adjust this problem....do I just go in and fatten my fuel map acrossed the board with the injector pulse rate?
thank you for any help
07-14-2008, 08:58 AM #2
- Join Date
- Jul 2005
- Jacksonville, FL
07-14-2008, 02:13 PM #3
You need to use your wideband and make a *real* curve for that MAF, even assuming what you are experiencing isn't a mechanical/physical issue, which it sounds like.
07-14-2008, 04:20 PM #4
07-14-2008, 04:24 PM #5
07-15-2008, 05:41 AM #6
I mean mechanical as in some type of failure or physical issue is very probable but the MAF could be that much different than stock.
In any case though, whenever a MAF is changed, the whole car has to be retuned. I seriously question your *need* to replace the OEM MAF in the first place unless it was just bad.
07-15-2008, 08:01 AM #7
i gonna take a look and see if I can find anything loose in the engine compartment here in a frew minutes and go from there...its sick how many small and big things can cause these codes...gonna try and do some logging this weekend
Will it hurt to run it till then? havent added or changed anything in awhile and the code just popped on sunday out of the blue. do you know how long it takes having a problem to set these two codes? i cleared the codes how long if there is still a problem till it pops back on?
thank you frost
07-15-2008, 08:12 PM #8
It could be hurt running it hard, for the DTC to set, the LTFT value has to be over +24% ! You could likely be significantly lean at WOT.
This isn't a tuning issue unless, say, it's done this since the MAF was installed. There are many conditions for this code and condition. The fact that both banks are reading lean is more of a blessing than you realize. It rules out a misfiring plug or an injector issue and shows that the problem is further up line. Check your fuel pressure with a cheap mechanical gauge at the rail if you don't have one. Try and check it under load as well.
07-15-2008, 08:35 PM #9
friday ill pick one up and a pressure gauge and go from there
thanks again frost!
07-15-2008, 08:59 PM #10
the filter is one of those things that everyone changes, but it hardly ever ends up being the culprit. It can't hurt though and I guess it's worth peace of mind.
Does the car ever stumble or jerk during moderate to heavy transitional throttle?
07-15-2008, 10:05 PM #11
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