check engine light codes i don’t know why. came up

[chevyaz]

So guys im driving around my truck is running fine and i get a check engine light. I checked the codes and I get a code 42 and 44 so what the heck does all that mean? Its a 94 gmc silverado truck with a 350 5.7 engine.

Topic

[Greg]

Electronic spark control circuit

And 02 sensor

[chevyaz]

My question is why thesr codes came up?

[Greg]

The 42 code could indicate an open or short to the ignition module or the ignition control is not working properly

The code 44 could be indicating a lean condition from a vacuum leak or it could have a broken wire or just not working anymore even a bad map sensor could cause a code 44 to light up the cel

On the 42 I would check wiring harness to see if anything is broken and then test the module to see if it is performing correctly.
On the 44 I would check for vacuum leaks and wires for voltage before condemning the 02 sensor.

[chevyaz]

So i replaced the ignition control module, o2 sensor, and seafoam the engine, so now in the morning i let it warm up for 5 minutes and drive it when i take off from a light it sputtering and when I floor it it will take off fine. When it warms up the sputtering when i give it some pedal goes away. Now it set a code 44 again .what the hell is wrong now?

[Rob megee]

If a 44 is a lean condition you could have unaccounted for air entering the system. Air is entering the system from someplace other than the the normal path. Could be a vacuum hose, could be an intake gasket or some other source.I would listen for a vacuum leak. You can also have the engine smoke tested. I am assuming that gmule has access to the codes. I do not. This is just general advice for a lean condition code. A smoke test pushes smoke into the intake system and the smoke will blow from where the leak is.

[chevyaz]

That doesn’t account for the sputtering when i give it some gas.

[Greg]

With the lean codes and the sputtering I would investigate the fuel system. Check fuel pressure and if you can look at the fuel injectors to see if they are spraying correctly. I have seen everything from a broken wire to an injector or the pig tails have deteriorated causing a bad connection. Since this is a tbi engine you can look down into the throttle body and see if they are spraying fuel.,

[chevyaz]

Tbi has just been rebuilt new injectors and regulator, replacing fuel pump tommorow. Tired of guessing at the little things. New fuel pump will help narrow things down.

[Greg]

Iirc fuel pressure should be about 12lbs for that vehicle.

[hondaguy453]

Have you done a resistance test on the spark plug wires? You can also run a screwdriver along the wires to check if it arcs on the screwdriver. If it’s dark outside you may also be able to see the voltage arcing from wire to wire if they are cracked. Also check the spark plug boots. I’ve had the same prob on chevy’s and gm’s and spark plug wires were causing the sputtering.

[Greg]

Should probably check your fuel filter while you are at it.

[chevyaz]

The new fuel pump fixed the problems. Dam thing hasn’t run this good in a long time. Finally no more problems.

[chevyaz]

Thanks gentleman.

[hondaguy453]

Good stuff! Thanks for posting the fix!

[Greg]

Glad to hear you fixed it

[Author]

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