WTF moment

[NateB1583]

Sorry for writing a book but I am totally confused. I will provide as much information here as I can and am hoping for some suggestions. I am no certified mechanic but I do work on cars and bikes pretty regularly although mostly simpler stuff on my cars and trucks. 

 

I bought a 13 Sierra with 190,XXX miles "as is" from a roadside dealer a couple weeks ago. Got it for 8k expecting to have to put a little money and work into it. I'm going to give a step by step on what happened because I do not know what caused what: No lights when I bought it but after about a week and a half it started throwing a code for 02 sensor. I picked up the 02 sensor on Friday and while I was at the counter I spotted a buy one get one free some brand or other of fuel injector cleaner. Picked up two and went to Shell and added the injector cleaner and filled the tank (worth mentioning the evap canister is plugged so it is a slow go filling up) then went into the car wash. Everything running great, I sat idle through the wash and pulled out after. As soon as I cleared the wash truck started dinging, traction control and stablitrack off lights lit up, check engine light started flashing, and the truck is running like absolute crap (clearly misfiring bad). I drove home (3-4 blocks) and pulled it into the garage. Replaced the 02 sensor and pulled the evap canister to blow out all debris. Started back up and still idling like crap misfiring. Took it to Oreilly's (right next to Shell) and had them run the codes and picked up plugs and wires. Sure enough, multiple misfires and emphasis on cylider 6. Went home and did the tune up. Old plugs were gapped easily 3x normal but saw no difference with #6 vs the others. After starting back up it still ran like crap so now time to google and youtube. A few hours later I went out to check for ticking (youtube says stuck lifters) and sounded great. Seemed to be idling totally normal so I decided to take it for a ride. Ran a little rough at first but the lights stayed off except check engine stayed solid. I hopped on the highway, got it to 70 then punched it. Once I got up around 100 the lights all came back on and check engine was flashing. Slowed back down to 70 and everything started working again. Did this twice more and same result. Got off highway and turned back and did it again but this time no lights. Tried a couple more times and still nothing, seems to be running normal again. Took it back to Oreilly's the next day to check the codes and I was told the only code was an ABS code and after they checked it the check engine light went off. 4 days later still running normal with only a little unsteady idle. I don't know if this is a problem with fuel injectors or if something got wet during the car wash and started running normal after it dried out. Anybody ever heard of something like this? Why the traction control and stabilitrack lights and ABS code?

[diyer2]

Plugged catalytic converters?

With those miles I would service everything and do a through inspection of the entire truck.

All fluids, belts, brakes, etc.

Starting with a properly maintained truck may avoid future problems.

 

[Snowcamo]

Two differnt injection cleaners. Run through the tank and fill up again. 

[Black02Silverado]

Who knows how long it sat at the used dealer lot.  So the fuel could be an issue.  Run  another tank of quality gas and a cleaner.  As stated above, do all the regular maintenance. Change all the fluids and filters, belts and check hoses.  

 

Water could have caused your issues.  Only way to tell is if it is running well for a few days, take it back through the wash and see if it duplicates.  

 

Keep an eye on the oil level.  If it is using a lot of oil, then over time and that many miles the Catalytic converts could be shot.

[NateB1583]

18 minutes ago, diyer2 said:

Plugged catalytic converters?

With those miles I would service everything and do a through inspection of the entire truck.

All fluids, belts, brakes, etc.

Starting with a properly maintained truck may avoid future problems.

 

That is the plan for sure. Did the oil first thing and have coolant and thermostat to do a flush. Planned on doing plugs and wires anyways, this just forced my hand sooner. Differentials and transfer case within the next week or so. PCV valve and air filter soon as I get back to the store. Didn't even think about the belts, will plan on those as well. Thank You. 

[NateB1583]

18 minutes ago, Snowcamo said:

Two differnt injection cleaners. Run through the tank and fill up again. 

Any recommendations on injection cleaner? Worked at Jiffy Lube several years ago and we did an IV type system. Is that necessary or better than the in tank style? Do they actually clean them well or is it still going to be necessary to change them?

 

Thanks

[NateB1583]

23 minutes ago, Black02Silverado said:

Who knows how long it sat at the used dealer lot.  So the fuel could be an issue.  Run  another tank of quality gas and a cleaner.  As stated above, do all the regular maintenance. Change all the fluids and filters, belts and check hoses.  

 

Water could have caused your issues.  Only way to tell is if it is running well for a few days, take it back through the wash and see if it duplicates.  

 

Keep an eye on the oil level.  If it is using a lot of oil, then over time and that many miles the Catalytic converts could be shot.

Will do. Thank You. I am dreading the next car wash but you are right.

[Jsdirt]

I'm betting on a bad connection, or ground, that got water in it from the car wash. Any problem that fixes itself is not a mechanical problem.

 

Bad connections and crusty connections are commonplace on modern vehicles now, especially in the salt belt, and especially with miles on them.

[Black02Silverado]

2 minutes ago, Jsdirt said:

I'm betting on a bad connection, or ground, that got water in it from the car wash. Any problem that fixes itself is not a mechanical problem.

 

Bad connections and crusty connections are commonplace on modern vehicles now, especially in the salt belt, and especially with miles on them.

Yes, it is a good thing to go back over all the grounding points, take them off, clean them up and put back on with some dielectric grease.  

[MaverickZ71]

1 hour ago, NateB1583 said:

Any recommendations on injection cleaner? Worked at Jiffy Lube several years ago and we did an IV type system. Is that necessary or better than the in tank style? Do they actually clean them well or is it still going to be necessary to change them?

 

Thanks

Use a couple of bottles of Chevron Techron Fuel System cleaner (not fuel injection cleaner, that they also sell) once in a while.  It's available at WalMart and auto supply stores.  The Owner's Manual says to use GM Fuel System Treatment PLUS at each oil change if you need to.  The GM stuff is the Chevron Techron Fuel System Cleaner, same bottle, but with a GM label on it.  

[NateB1583]

15 minutes ago, MaverickZ71 said:

Use a couple of bottles of Chevron Techron Fuel System cleaner (not fuel injection cleaner, that they also sell) once in a while.  It's available at WalMart and auto supply stores.  The Owner's Manual says to use GM Fuel System Treatment PLUS at each oil change if you need to.  The GM stuff is the Chevron Techron Fuel System Cleaner, same bottle, but with a GM label on it.  

I will do that after I run this tank out (shouldn't take long ;) ) Thank You

[NateB1583]

47 minutes ago, Jsdirt said:

I'm betting on a bad connection, or ground, that got water in it from the car wash. Any problem that fixes itself is not a mechanical problem.

 

Bad connections and crusty connections are commonplace on modern vehicles now, especially in the salt belt, and especially with miles on them.

This is what is leaving me confused. If its the fuel injector's and the cleaner initially "broke something loose" then maybe started clearing it out after a few rides (not sure that's how the stuff works). If it was that the car wash getting something wet, I had no idea what could have gotten wet to cause this. I did not know a ground could so I will definitely dig into it after work today and clean and tighten up connections. Thank You

[NateB1583]

51 minutes ago, Black02Silverado said:

Yes, it is a good thing to go back over all the grounding points, take them off, clean them up and put back on with some dielectric grease.  

I will do that tonight. Thank You

[jjt]

The O2 sensor code is a good indicator that the catalytic converter is plugged I would also check the catalytic converter as stated above. I had this problem with  a truck before and the dealership made me change out O2 sensors, spark plugs, did a full tune up and diagnostic. The bill was over $1000.00 CAD and the truck still ran like crap. I was so pissed off when a muffler shop technician figured it out just by sound, but a dealership with a full diagnostic machine couldn't.

[NateB1583]

6 minutes ago, jjt said:

The O2 sensor code is a good indicator that the catalytic converter is plugged I would also check the catalytic converter as stated above. I had this problem with  a truck before and the dealership made me change out O2 sensors, spark plugs, did a full tune up and diagnostic. The bill was over $1000.00 CAD and the truck still ran like crap. I was so pissed off when a muffler shop technician figured it out just by sound, but a dealership with a full diagnostic machine couldn't.

How do I check the catalytic converter? Is it something that can be cleaned or does it have to be replaced once it's plugged? Since I replaced the 02 sensor (Sensor 1 Bank 1) the check engine light has gone away and code cleared. I would still like to check it out if needed though.