Dear Friends:


I couldn't check the pressure, but looked at the freeze data. It said that at the time of the code, the fuel pressure was 54. What should it be? I wonder if the MAF sensor is problematic. How can I tell?


I thought it helpful to see all the freeze data when the code occurred:


Trouble Code: P0171
ABSLT TPS (%): 12.2
Engine Speed (RPM): 1,254
CALC Load (%): 22.7
MAF LB/M: 2.3
MAP ("HG"): 16.2
Coolant (F): 154
IAT (F): 52
ST FTRM1 (%): 6.3
ST FTRM2 (%): 8.6
LT FTRM1 (%): 12.5
LT FTRM2 (%): 11.7
Vehicle Speed: 16
Fuel Pressure (PSI): 54
Fuel Sys 1: Closed
Fuel Sys 2: Closed


Maybe you can make heads or tails of this information and give me some advice. Thanks a bunch as always.

Thanks

 

You have too little data as yet. You can guess and spend $$$ or get more data. Much cheaper (and easier) to get data. Look at fuel trims, engine hot, parked, at idle & about 2500rpm.

That code usually shows an air leak not a bad MAF but OBD will show you.

 

Dear Friends:


I wanted to follow-up on this post and close-out what is happening. Initially, I tried some Chevron Techron Injection Cleaner and the engine started running normal again and I cleared the codes and all seemed well.


After a day or so and nearly 100 miles, it coded again with P0171 & P0174 running lean. The car seemed fine, but there the codes were.


I decided to try some BG44K as suggested and ran that tank through. It seemed a bit better, but codes continued to come.


Then I decided to change the fuel filter thinking that it was time... and it was. For about a day, it seemed to fix the problem and then.... it coded again.


In looking at the Freeze Data on several subsequent codes, I noted that the fuel pressure was normal, 55-60 lbs. Since the car was running well and the Freeze Data indicated the pressure was fine, I looked elsewhere.


I considered the MAF Sensor, but decided to hold off. I decided to drive it, clearing the code. It seemed that it only coded when I was parked and leaving the engine running. That was new and the time it coded seemed to be longer and longer between clearing the codes.


I could detect a slight ping and added Octane Boost and the ping went away, but still the error codes.


I bought four bottles of the Techron Injector Clear additive and after one tank I noticed that the ongoing code would go away, but that the engine light stayed on until I cleared it. It became intermittent so I continued. I noticed on the second tank while I was idling for about 30 minutes that the code and engine light went away. That was several days ago and a full tank.


My only guess is that the injection system was really dirty or something in it needed time to come out. I am not a mechanic as I am sure you can tell.... but, no more code and I am thrilled that it wasn't something big and costly.


Have a great week and thanks to all that gave me suggestions. It really does help.

 

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