2015 wrench icon/catalytic

[kdixon1029]

Wife called and said wrench icon and it was dead! I went to pick her up and it started and drove home. I replaced the throttle body (didn't clear KAM) and all is well. I've always had the P0420 code since we've bought the truck. I decided to get on the gas on the interstate to see if wrench icon would reappear. It did not, however the check engine light started flashing and it began stuttering and came to a stop just as it did with wrench icon. It did start right back up and drove fine. I checked codes and had several new codes in addition to the P0420 including a throttle body code which I found strange. Maybe it was still in memory?? Any how a tech told me that the cat could be causing all of this trouble. If the exhaust has nowhere to go it backs up causing the misfire codes I had. So I'm researching troubleshooting the cats and got an infrared thermometer but both cats are cooler before the cat and warmer after by about 45-50 degrees, Which indicates they are functioning. The truck has began to rough idle as before I replaced the throttle body but is driving well. I'm currently ordering the OBD to hook to forscan but have no experience using it. I'm stumped. Anyone have experience with this issue?
thanks

 

[JasonH]

Rough idle and stumbling during heavy throttle could be plugs. I just regapped one because it opened to .032 and was causing noticeable stumbling under heavy acceleration. I thought it was my leaking exhaust manifold but turned out the plug was the cause. Try checking your plug gaps. Make sure none are over .030.

 

[kdixon1029]

Thanks, I'll check that out. What do you make of the p0420 code and the cats temp reading ok?

 

[JasonH]

Thanks, I'll check that out. What do you make of the p0420 code and the cats temp reading ok?

Honestly, no clue. Perhaps a cat was fouled from poor combustion? Maybe try swapping plugs, drive the crap out of it to heat the cats and reset the codes. I've only had the cat code on one vehicle and I sold it shortly thereafter for other reasons. Strangely, running lacquer thinner in the fuel cleared the code temporarily, but it always came back eventually so something was probably amiss. You can find instructions for the lacquer thinner online.

 

[kdixon1029]

I hope to get time to check plugs this weekend. Last warm day for the boat today! The tech I spoke with said same about plugs as I was getting misfire on 2 cylinders as well as can shaft sensor, IAC sensor and the throttle body code when I got on it. He was explaining that if the exhaust couldn't flow out it would come back in to escape somewhere and that was causing the plug misfire. At this point I'm wiling to give anything a shot! Once this is corrected then it's on to tackling the oil leaks. fun times ahead

 

[99WhiteC5Coupe]

I hope to get time to check plugs this weekend. Last warm day for the boat today! The tech I spoke with said same about plugs as I was getting misfire on 2 cylinders as well as can shaft sensor, IAC sensor and the throttle body code when I got on it. He was explaining that if the exhaust couldn't flow out it would come back in to escape somewhere and that was causing the plug misfire. At this point I'm wiling to give anything a shot! Once this is corrected then it's on to tackling the oil leaks. fun times ahead

If your engine has iridium plugs - GM has issued a TSB stating not to adjust the spark plug gap on the iridium plugs, as it can damage the iridium coating.

GM recommends discarding the plug and replacing with one that is within gap specifications out-of-the-box. Any new iridium plug that is not within the gap specifications should be discarded.

 

[Ryan L]

My 2016 Limited uses iridium plugs. When replacing them at 100k, 2 of 6 plugs needed very slight gap adjustments. Did not use the old $.99 keychain gapper tool, and instead used the newer tool design that only touches the ground electrode (which is not iridium plated). The tool sort of resemble a bottle opener. Being very careful not to touch or disturb the iridium coated center electrode, adjustments are definitely possible. But that’s my own experience, YMMV.

 

[Utah Driver]

Ford Vehicles: Electronic Throttle Body Calibration Procedure

Here is the jumper leads I used in the video, for the price they are worth it to do it right, you can buy them here-http://www.amazon.com/gp/product/B0002JJU...

youtu.be