Weird misfire in 2004 chevy tahoe

[Mejo]

I have bought a 2004 chevy tahoe and it has missfire.
I have changed all spark plugs, spark plug wires, O2 sensors, and knock sensors with their wire.
I also cleaned the MAF sensor, throttle, intake manifold, and intake manifold sensor.
All of my Injectors were tested and they work.
What could have caused the missfire?
I have the following codes in my car:
P0120 Throttle Position Sensor (TPS) 1 circuit
P0169 Incorrect fuel composition
P0178 Fuel composition sensor circuit low frequency
P0179 Fuel composition sensor circuit high frequency
P0220 Throttle Position Sensor (TPS) 2 circuit
P0300 Engine misfire detected
P0446 Evaporative Emission (EVAP) vent system performance
P0449 Evaporative Emission (EVAP) vent solenoid control circuit
P1516 Throttle Actuator Control (TAC) module throttle actuator position performance

Looking forward for your help.
Most appreciated.

 

[S33k3r]

I can't answer all of these, but I'll give a go at what I am able to:

>> P0120 Throttle Position Sensor (TPS) 1 circuit
This seems like this sensor needs to be replaced.

>> P0169 Incorrect fuel composition
>> P0178 Fuel composition sensor circuit low frequency
>> P0179 Fuel composition sensor circuit high frequency

These three would seem to be correctable via replacing the Fuel Composition sensor.

>> P0220 Throttle Position Sensor (TPS) 2 circuit

This suggests the Throttle position sensor is bad

>> P0300 Engine misfire detected

This one could be resolved by fixing all of the above. Alternatively, you have a bad coil pack. I'd get the other stuff corrected and see if this goes away first.

>> P0446 Evaporative Emission (EVAP) vent system
>> performance
>> P0449 Evaporative Emission (EVAP) vent solenoid
>> control circuit

This is an annoying one. No part is super expensive, but they are often time consuming to fix. Do you have any issues completely filling the tank?

>> P1516 Throttle Actuator Control (TAC) module
>> throttle actuator

This suggests the module that actually controls how much gas you are giving your rig is bad. I suggest resolving these items and then rechecking codes:

P0120 Throttle Position Sensor (TPS) 1 circuit
P0169 Incorrect fuel composition
P0178 Fuel composition sensor circuit low frequency
P0179 Fuel composition sensor circuit high frequency
P0220 Throttle Position Sensor (TPS) 2 circuit

Good luck. Nothing on your list is super expensive, but they are all pretty big time sinks.

 

[Fless]

Welcome to the Forum from Colorado!

A few suggestions since you seem to have a capable scanner:

P0169 Incorrect fuel composition
P0178 Fuel composition sensor circuit low frequency
P0179 Fuel composition sensor circuit high frequency
Will your scanner read the fuel composition sensor frequency? There is a range that is acceptable, and I'll try to look that up and post it. If you have access to diagnostic info, it would be in there.
What fuel is in the tank (E0, E10, E15, or a version of E85 -- how much alcohol)? What does the scanner say the alcohol % is (I think it's in Engine Data 2 in your scanner)?
The fuel composition sensor can be a bit pricey: cheap ones run under $200 but the GM OE will run about $400 on Rock Auto. My Upull has lots of these in wrecked trucks, and with the engines & trannies pulled and out of the way they're not that difficult to remove. And inexpensive.

------------------------------------
P0300 Engine misfire detected
General misfires like this can be caused by a faulty crank-cam sensor correlation. Your scanner should have a CASE relearn that can be done in a few seconds if the engine is warm. Do it just to rule it out. Also look at live data to see if any individual cylinders are misfiring.

------------------------------------
P0446 Evaporative Emission (EVAP) vent system performance
P0449 Evaporative Emission (EVAP) vent solenoid control circuit
Typically this is the fault of the canister vent valve that is under the rear of the truck, somewhat above the differential. While tests can be done on it and the circuit, it's an inexpensive part to replace and a common issue. If you want to test it, it should be closed (no air can pass through the ports) when 12v is applied to the terminals (polarity doesn't matter). When no voltage is applied, air should be able to pass through the ports. They can be intermittent, or the foam filter plugged, etc.

 

[rockola1971]

A TAC Module rarely fails. The TPS lasts well over 100k miles but after that all bets are off. Most Drive by wire failures can be attributed to the wiring harness that plugs into the TPS or the TAC Module. Most of the time its the TPS harness. A wire will get a break in it which causes intermittent electrical open. The wire (stranded) will be broken but the insulation on the wire will not be so its a hard visual to catch. You have to pinch each wire from the TPS plug with two fingers and run your fingers away from the plug about 12". Usually the fault is within 6" or so of the plug. The TAC module wire harnes failure almost always happens right where the wire enters the plug so it is definitely a fun one to find and diagnose.