P0304 code and lights all over dash lit up

[slyhog022056]

Last week my 2010 yukon XL with 5.3 started a #4 cylinder misfire, traction control light on, stabilitrac lights on, tires pressure light on. Throwing only 1 code, P0304 code. When reset it comes back on within 5 seconds.
Changed coil packs, ignition wires, plugs. No change. Not sure where to go from here. It misfires so bad the the traction control kicks in and out when turning sharply like a lock rearend. Idle swings 400 to 1000 at idle. The trans wont even shift correctly.
I did fill up with gas 3 days before this happened but it is the same place I always fill up all my vehicles.
I have a bad feeling it the AFM lifters.
Any suggestions for where to turn too next appreciated.

 

[intheburbs]

Usually, multiple unrelated warning lights are a symptom of low voltage.

I would:
1) Check for loose battery cables
2) Check for loose/damaged grounds
3) Check the battery
4) Check the alternator

Any auto parts store will check the battery and charging system for free.

 

[OR VietVet]

Track your wiring harness(es) for the coils and injectors and make sure they are tight, intact, corrosion free.....Any recent work on the rig?

 

[slyhog022056]

No work in my truck engine at all, 225K on the odometer. I did find out the misfire will cause the lights for traction control and stabilitrac to come on because of the misfire. getting power out of all the coil wires ( just installed new plugs, wires and coils) all the plugs were pretty black and crusty.
Thinking it might be a stuck DOD lifter in #4. but I do not hear any ticking like a collapsed lifter nor a p030 code for DOD problem.
I just cant think of anything else that would cause misfire. I guess I will have to remove the valve cover and see if I have a loose rocker. I would do a compression check but it is nearly impossible to get anything into that plug hole without removing the inner fender cover.

 

[OR VietVet]

A bad ground can cause an injector problem and plugs, wires and coils can be fine. You may well have a lifter problem but digging in to that is way more aggressive than searching for injector ground(s) first.

 

[swathdiver]

Well, do you have a scan tool that can show misfires by cylinder? Can you pull the rocker cover on the passenger side and inspect the valve train or even let it run for a minute and watch cylinder 4 in operation? If you can do either of those, you'll know right quick.

 

[glowingbubble]

did u ever figure out ur issue i have same problems i have a 2008 tahoe was working fine all sudden engine light started blink car was loosn power misfiring . I checked light code says #4 misfiring i change spark plug wires , spark plugs and coil n injector for #4 i then reset code and its still sayn same code n nothing has changed any suggestion

 

[OR VietVet]

Thanks for the 1 period and 1 comma.

 

[j91z28d1]

did u ever figure out ur issue i have same problems i have a 2008 tahoe was working fine all sudden engine light started blink car was loosn power misfiring . I checked light code says #4 misfiring i change spark plug wires , spark plugs and coil n injector for #4 i then reset code and its still sayn same code n nothing has changed any suggestion

do you know how to check for spark in they cyl?

 

[j91z28d1]

Thanks for the 1 period and 1 comma.

one to many of you ask me lol