MAF sensor code P1174
TReK
Joined: Feb 2009
Posts: 2,186
Likes: 200
From: Linden, NJ
Sorry to thread jack, but what are your fuel trims. They will give you an indication of where to look next. I also had these codes a couple months back.
How's your purge valve? Gas Cap?
My trims indicated the ecu was adding fuel to compensate for unmetered air. After ruling out vacuum leaks I decided to replace the purge valve with the Hyundai unit and an stant gas cap off Amazon. No more codes and fuel trims stabilized to a healthy steady +/- 3%.
With your intent to replace fuel injectors sounds like your ecu is pulling fuel. Do you believe they are leaking?
How's your purge valve? Gas Cap?
My trims indicated the ecu was adding fuel to compensate for unmetered air. After ruling out vacuum leaks I decided to replace the purge valve with the Hyundai unit and an stant gas cap off Amazon. No more codes and fuel trims stabilized to a healthy steady +/- 3%.
With your intent to replace fuel injectors sounds like your ecu is pulling fuel. Do you believe they are leaking?
I have never heard of fuel trims. Sorry. I am limited to interpreting codes, faults, and general diagnostics on vehicles with ECU's. I just know TR-6's and the good ole' British Leyland days.
Winching
Joined: Sep 2010
Posts: 745
Likes: 141
From: Fairfield County, CT
I have the ultra gauge, which fuel trim should I be looking at? The long trim or short trim?At what point should I consider the reading? At idle with engine warm? Got 1171 & 1174 right at start up and then when I pulled into work after 40 min of mainly highway driving.
Mudding
Joined: Mar 2016
Posts: 192
Likes: 12
I've had P1174 for a few weeks now but no CEL (pending code).
Truck runs OK, maybe a little on the rough side, but fuel consumption could be better (I get ~400km to a tank).
The research I've done points towards vacuum leaks being the cause, not MAF. I have upper intake manifold gasket, valve covers, throttle body gasket all ready to go and will let you know if it fixes the issue. Next on my check list would be injector o rings and exhaust manifold to y pipe gaskets...
Truck runs OK, maybe a little on the rough side, but fuel consumption could be better (I get ~400km to a tank).
The research I've done points towards vacuum leaks being the cause, not MAF. I have upper intake manifold gasket, valve covers, throttle body gasket all ready to go and will let you know if it fixes the issue. Next on my check list would be injector o rings and exhaust manifold to y pipe gaskets...
4wd Low
Joined: Oct 2016
Posts: 11
Likes: 1
I had the p1171 and p1174 on my '01 that I had traced down to be dirty/sticking fuel injectors. This was on a vehicle that I bought with a blown headgasket and had sat for 5 years. I ended up doing the headgaskets etc so I had already replaced the injector o-rings. About 800 miles in, it started to idle ruff and had the two codes. According to my scan tool, all the O2 voltages looked good as did the MAF. It also draws about 18lbs of vacuum at idle. so I pulled the plugs, three of which had white ground electrodes. I pulled all the injectors and bench cleaned them with the jig I made using PB blaster followed by Techron fed through them via compressed air and a 12v trigger. All the patterns were ruff to begin with and two were sticking but after cleaning they all had a nice clean spray. It runs better than ever now and the codes cleared themselves. Truck has 122K on it.
Camel Trophy
Joined: Dec 2009
Posts: 3,885
Likes: 955
From: Charlotte
Good luck. I hope the MAF solves the problem for you, although I admit I am skeptical based on what I said before that the code is for Bank 2 only. Please come back and let us know how it turns out, one way or the other. Again, good luck.
Mudding
Joined: Mar 2016
Posts: 192
Likes: 12
yeah I know that was a dick comment, but why ask for advice and the do the opposite of what ppl are recommending?
I have a mortgage. I have no usable garage, let alone a work shop. Three kids that need constant attention, and a Wife. Time is a luxury. So a drop of $100 bucks for a hail mary approach seems reasonable to me. Sorry to hurt your egos, but I have to take it one long step at a time.
