[04SilveradoMykk]

My 2004 Silverado has a fuel injected Small Block Chevy in it, mated to the trucks original 4L60E

I am battling all of the fuel injection woes that go with swapping an engine into a truck it never came with. My engine is stuck in open loop with MIL codes saying bank 1 & 2 oxygen sensors aren't responding.

And I have a feeling the codes are keeping the PCM in a drivable "limp" mode, yet are preventing the function of the PWM & TCC solenoids.

I have the TCC solenoid on a manual toggle just to lock the TC at cruise to keep trans temps down.

However I am unsure of the the PWM solenoid. I am assuming that the PCM "limp mode" that's preventing the TCC to lock also prevents the PWM solenoid from doing it's thing?

How would a 4L60E trans act without the PWM solenoid, would it feel like excessive transmission slippage until the TCC locked? My engine will rev right up to the 3200 stall of the converter before begining to accelerate with any torque. Yet today, I think my PCM temporarily pulled out of this limp mode and the truck drove better than it ever has. Tons of torque, it didnt excessivly rev before beginning to move, the shift felt nice & strong and it was great. Than the flashing MIL came back with the O2 codes and the trans began to do it's old thing.

Does it sound like I'm on the right path?

Cheers ~Mykk

[carsavvycook]

Do you still have the MAF from the 2004 hooked up, with no air leaks between it and the throttle body? Also since the O'2 sensors are not responding, can you tell if it is too rich, or too lean?

I would think it is too rich, not allowing it to go into closed loop. I have found the MAF to be a cause of this, along with the coolant temp sender.

Check all of your sensor ground wires, to make sure they are clean and tight.

[04SilveradoMykk]

Thanks for the input. The MAF is still hooked up, not triggering any MAF codes and I can watch the flow rate via my scanner. The MAF & ECT sensors appear to be functioning just fine.

[carsavvycook]

Originally Posted by 04SilveradoMykk

Thanks for the input. The MAF is still hooked up, not triggering any MAF codes and I can watch the flow rate via my scanner. The MAF & ECT sensors appear to be functioning just fine.

There is one 'key' word in your statement that causes people to overlook some sensors, "appear". They may 'appear' to be functioning just fine, only because they are still sending a signal to the PCM, and not setting a code for themselves. Here is an example, a dirty MAF will not set a code for itself, but you will see the codes P0171, or P0174, or both, bank 1, or bank 2, or both banks running too lean. Common sense tells you to check fuel pressure, and volume, along with checking for any vacuum leaks, or exhaust leaks prior to the O'2 sensors.

One miss leading case in point, was a 1997 Ford Explorer 4.0L, with these same 2 codes had a dirty MAF. I cleaned it and the engine smoothed out, so the customer took it on a recommended drive, to get enough of the monitors to set as ready. He came back, and said it ran better up hill but still had the same codes. So I took a fuel pressure, and volume test, and put a fuel filter in it. During the removal of the fuel pressure adapter, I dropped it, and had to unbolt the coil pack to retrieve it. After completing the repairs it started up with multiple miss fire codes pointing to the coil pack. He had called his daughter to pick him up so they could go to lunch, and while he was gone I replaced the battery cable ends which were corroded. We had discussed this repair for a later date. He admitted it needed these repairs, and took it back on the same drive. He came back and said at ran great with no check engine light, and took it back to the smog only shop, it passed this time. All because of the battery cable connections.