WTF moment

[NateB1583]

Well, after several days no lights and no problems i was riding home in a downpour yesterday and all the craziness started happening again. Same traction control and stabilitrak lights, same blinking check engine light, same misfires. I limped home and parked it in the garage this time pretty sure its water related. Sure enough woke up today and started it up running perfectly and no lights. Was still getting codes for the same O2 sensor i already replaced so im going to water and heat seal the connectors then take it through the car wash. If it happens again ill try spraying a little water around cylinder #6 (where the misfires seem to be happening) and see if its sucking water in somehow. 

[MaverickZ71]

22 hours ago, NateB1583 said:

Well, after several days no lights and no problems i was riding home in a downpour yesterday and all the craziness started happening again. Same traction control and stabilitrak lights, same blinking check engine light, same misfires. I limped home and parked it in the garage this time pretty sure its water related. Sure enough woke up today and started it up running perfectly and no lights. Was still getting codes for the same O2 sensor i already replaced so im going to water and heat seal the connectors then take it through the car wash. If it happens again ill try spraying a little water around cylinder #6 (where the misfires seem to be happening) and see if its sucking water in somehow. 

Yep, Lucas fuel additive isn't going to fix anything that Chevron wouldn't.  Like you've come to realize, you've got a mechanical problem of some kind, probably a bad ground or short somewhere.  

[NateB1583]

1 hour ago, MaverickZ71 said:

Yep, Lucas fuel additive isn't going to fix anything that Chevron wouldn't.  Like you've come to realize, you've got a mechanical problem of some kind, probably a bad ground or short somewhere.  

After the most recent rain incident I taped up all 4 of the O2 sensor connectors and used some heat shielding tape over top of the #1 bank 1 sensor wires that are located right above the header. After that I took it over to the local car wash and got the $15 "ultimate triple underbody wash" to test it out. Made it through without an issue and ran great after. I am not sure how it was causing it but I believe it was O2 connectors getting wet that was causing the engine misfires. Time will tell for sure but I believe for now problem is solved. Will keep posted if anymore issues. Thank you to everybody who helped. 

[Doug_Scott]

GM needs to correct the traction control and stabilitrac shutting off error messages.  They know why it is happening, they know it will go away in the next millisecond or so, btw, I forget, do they give the driver a message saying "nevermind" when they turn those two things back on? 

[NateB1583]

12 minutes ago, Doug_Scott said:

GM needs to correct the traction control and stabilitrac shutting off error messages.  They know why it is happening, they know it will go away in the next millisecond or so, btw, I forget, do they give the driver a message saying "nevermind" when they turn those two things back on? 

It is very misleading. Not that the blinking check engine light and the beep aren't already alarming but the others going as well are enough to make you panic the first time it happens. So far they just show a message saying "Stabliltrak: On" and "Traction Control: On" after it starts working again. 

[Jstevens7700]

Completely guessing here but have you checked the fuel pressure? While my pump was going out i got o2 sensor codes. Also cleaning the grounds are never a bad idea. 2 on the back of the block with the right wobble socket and wrench all you have to remove is the vortec cover on the motor. 2 under the truck about even with the driver door on the frame. 2 on the same side and frame rail but about under the headlight then one running from the battery to the side of the block. Like i said not sure just wanted to throw the possibility out there

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[NateB1583]

So I thought this problem was solved as I have had no trouble for a few months. Recently it has acted up the same way a couple more times, water related. I took a spray bottle last night and crawled underneath spraying down each O2 sensor then the wire connectors that I had tape up. No problems there. I popped the hood and started spraying around. Started with the wiring related to the O2 sensors. Then sprayed the plug wires to see if anything was slipping by. No problems. Moved to the purge valve solenoid and hoses on drivers side of the engine and still nothing. Sprayed hoses directly above the throttle body and the truck started misfiring and alarms going off. I turned it off and blew everything dry with my air compressor, pulled the air box and hose assembly to inspect for cracks, then put back together and restarted and still running like crap. Next day same symptoms. Not sure exactly what caused it but i'm thinking that maybe the throttle body seal is bad and allowing water to suck into the engine? Maybe ran down beneath to something else? When I got up this morning I started it up then sprayed some starter fluid all around the throttle body expecting it to rev but nothing. I will pick up a seal and change it after work but if not that any suggestions? I'd hate to nuke the motor trying to troubleshoot this problem.