I have a 2003 H2 with a magna SuperCharger that is getting P0172 rich in bank 1 error code.

Here is events my h2 has been having

1. I was running lean in bank 1
2. I cleaned the Mass Air Flow Sensor with air
3. I then replaced the Mass Air Flow Sensor
4. I then noticed there was a tear in the 4 inch pipe that connects after the Mass Air Flow Sensor so I replaced the pipe.
5. soon after I replaced the pipe I started getting bad gas millage and p0172 error came up.
6. I replaced both bank 1 oxygen sensors and cleared all codes
7. after a while the p0172 code came back on
8. After the MAF and the O2 sensors I am left confused on what to try next

I was told that the vehicle was compensating for to much air when i had the tear in the pipe so it ran lean but now that the tear is fixed it is trying to adjust. I have cleared the computer at east 4 times after the fix . Will it fix its self or does anyone know what to try next?

 

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Is the new MAF Sensor the same as the old one you replaced? It's not getting enough air flow that's why your getting rich condition, more air then it would lean up. Try putting the old sensor back and see what happens. That should be your only problem cause you already replaced the o2 sensors....

 

Hi thank you so much for your input on my problem.


I will try swapping back to the old maf to see what happens. It usually takes a week or so for the light to kick on with the codes. someone said it might be after so many ignition cycles.


over the weekend I put sea foam in the gas to clean the injectors. I towed a 6000 lbs boat a total of 7-8 hours at 60-65mph with no engine light kicking on. right after I filled up the gas tank the 3rd time the light kicked on again. it is the p0172 and p0175 I don't know if the po1075 is a new code or if I was just not scrolling on the computer. I think I would have noticed the p0175 before. This is such a weird problem because this all started with a p0171 t(to lean) code when I had the leak in the intake pipe after the maf sensor. After I fixed the leak the system codes with p0172 (to rich) I would think that the leak repair would start to correct the long term fuel trim. the magic question would be how long does it take to correct the long term trim and does confuse the system if I am towing a boat every weekend on long trips.


I also wonder if something like the injectors or something got dirty from bringing in un filtered air. I really appreciate everyone's input on this. it

 

Try this....
1. Disconnect the negative (-) and positive (+) battery cable.
2. Touch the negative (-) and positive (+) battery cable for about 1 minute, the longer the better. This will discharge the capacitors inside the ECM and will hard reset the ECM.
3. Reconnect the positive (+) and negative (-) battery cable.
4. Let it idle for about 10 - 15 minutes so the ECM will learn the repair that you did.

Hope this helps!

 

After you disconnect and reconnect the battery, you need to let it idle for 20 mins, drive it on a freeway on a steady speed for 20 miles. Fuel trims cycles 3 times before it stablelized, rule of thumb, after those cycles the fuel trim must not be higher that +5 and not lower than -5. Some cars runs fine going a little beyond those points, but some don't...

Good luck!

PS: I wouldn't try shorting the power just to drain the power in the ECM like what mentioned above..

 

Thank you for all your input I have tried all of the above and I am still getting the error code" rich In bank 1 " (code p0172) I have also just replaced the pcv valve and still nothing. Do you or anyone have any more ideas?

 

Sounds like a clogged injector to me which would make sense not showing the code while towing.

Try another can of Sea Foam or a few caps of Marvel Mystery Oil. I would pull the lugs too, it might help pinpoint which injector is bad.

TH

 

had this issue a long time ago. the air intake hose tore between the air filter and the magnuson blower. I sucked dirt into my engine and threw up codes. Ended up having the blower rebuilt (it had almost 90k miles on it anyways). Magnuson in ventura California was awesome. they rebuilt it for 400 bucks. did a compression test on the engine and it came back fine so I didn't address that. that was 30k miles ago and its still fine so I got lucky. the codes cleared themselves after a week or so.

 

thanks guys for the input.

i will drop another can of sea foam with my next fill.

how do i pull the lugs / check the injectors?

i was idling the other day when it was 100 degrees out. I had a bank one misfire and then a separate code later for multiple misfires

i just bought a cen-tech 60694 CODE READER from harbor freight WITH LIVE DATA. it is supposed to read o2 sensors etc. and record. does anyone know what I should be looking for on this thing. or what the o2 sensors should be reading

maf air flow rate?
o2 sensor outputs?
short term fuel trim reading?
long term fuel trim reading ( example mine is -7.8)