5.7 tbi DTC 44 backfiring and missing intermittently.

[Cng2500hd]

Just got my 90' k1500 on the road and 2 day's later it gets a cel,starts missing and backfires if I stay in it. The code shows to be lean bank 1. I have a new fuel pump, filter's, plug's, wire's, cap and rotor. Any idea's what it may be?

 

[PlayingWithTBI]

The code shows to be lean bank 1. I have a new fuel pump, filter's, plug's, wire's, cap and rotor.

Code 44 is for lean exhaust, TBIs only have 1 O2 sensor so, it can't tell you if it's bank 1 or 2. Since you changed the fuel pump and filter have you checked your fuel pressure? The regulator spring may be broken or weak. You may have a split in the little hose that connects the fuel pump to the sender unit.

If it's misfiring you can get a lean code due to un-burned fuel resulting in high oxygen content in the exhaust. A bad coil and/or ICM can cause this too.

https://www.freeautomechanic.com/gm-code-44-lean-exhaust.html

 

[Schurkey]

^^^ Yup.

Connect a scan tool, look at the data stream. Find out what the computer is trying to tell you.

Verify fuel pressure; verify ignition timing including timing advance.

And make sure both fuel injectors seem to be squirting an equal amount of fuel.