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Hey guys ... I'm getting P0172 & P0175 popping up regularly on my swap. Just to recap ... 2004 5.3L truck engine with less than 5K on it now it is new basically. Put in a 1989 silverado. Oh ... and of course a Nelson Tune :thumb: ... Truck runs fine with no obvious issues. Just keep getting Rich bank 1 and Rich bank 2 I've monitored the live data on the sensors and nothing seems to be wrong with the numbers I'm seeing. Just wanting some fresh ideas....
Thanks,
Brian
Check the fuel pressure, the most overlooked thing I can think of.
Causes:
A code P0172 may mean that one or more of the following has happened:
The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters (K&N, etc.) can cause the MAF to become dirty if the filter is over-oiled
There could be a vacuum leak.
There could be a fuel pressure or delivery problem
Possible Solutions:
Possible solutions include:
Inspect all vacuum and PCV hoses, replace if necessary
Cleanthe MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect fuel lines for cracks, leaks, or pinches
Check the fuel pressure at the fuel rail
Check the fuel injectors, they may be dirty. Use fuel injector cleaner or get them professionally cleaned/replaced.
Check for an exhaust leak before the first oxygen sensor (this is unlikely to cause the problem, but it is possible)
Another problem can be the MAP sensor giving inaccurate data. Check your barometric pressure in your area with the national weather service and compare it to the reading you get from any measuring software. My sensor is at the rear of the intake manifold and has two fitting on it. The large one goes to the brake booster and then there is a very small vacuum line that should be blocked off or connected some where so you don't have a leak.
damn redheartbeat!! you're all over these questions, way to go and thanks for helping out the members with their questions!!
later,
allen
Thanks guys for the ideas.
I did check for vac leaks already and didn't see any. Need to verify fuel pressure and it does have a K&N in it so I'll have to check that.
I'll post what I find.
Later,
Brian
dang it .... today it dieseled after I shut her off ... WTF?? No codes but something isn't right. I got to dig into this sucker and find out what's going on.
dieseled? That's not possible unless fuel is available. You've either got too much fuel pressure or dirty injectors. An engine can't diesel without a supply of fuel.
Red,
I know .... you should a seen my face when it did it. :eek:
I got called out of town today ... can't dig into it till I get back... Got to do a full diag on the fuel system and check it from stem to stern.
You probably are close with that bad injector. Strange though this engine has less than 5k on it total. Unless something got in the lines during install. I'll post what I find.
Thanks
Yeah, that's damn odd that you'd have something in there to dirty up an injector in only 5k. The injectors have a filter on the top end of it's body to catch garbage. You couldn't have a short somewhere feeding voltage to the injectors could you?
strange things happen to fuel injection systems when stored over time.
even new LT1 engines 10 years old have stuck or dribbling injectors
a few whacks with a hammer and usually ok, if not pull injectors and
have them sonic cleaned.
airdeano
bad injectors are very possible, when i took my 04 truck in for service i looked at the history of my :smile: truck and found G.M. replaced 1 bad fuel injector with 1 mile on my truck! i bought it with 2 miles on it. the mech said some 04 trucks have 1 or 2 faulty injectors that usually show up during the early stages of use, and warranty fixes them, other than some times a radio going bad he said not a lot of probs on 04s.
The injector flow rate could be too small in the PCM, you could have Allen doublecheck that for you. I didnt know my sis' Tahoe had the E85 injectors in it, and when I flashed a regular stock file to it, the trims went -25 and set the codes.
Chris
If you are going to clean the injectors i have found that BG fuel injector cleaner and then a can of their 44K in the tank works awesome. You would have to have the OTC tool to hook into the fuel rail or just go to a shop that uses BG products and has the injector cleaning tools.