Rough idle after rock sliders were welded on

Does anyone know why my 2001 3.4 DCSB would have a rough idle after having some rock sliders welded to the frame? Any reasons y'all can think of would help!

It ran and idled fine up until I drove off from the shop I had the sliders welded at. It started up just fine and idled fine before I left the garage bay. Once I got to the first light I had to make a complete stop, that's when I felt the engine start to idle rough, almost like its gonna bog out but not quite that bad. Once I accelerate its fine and runs smooth as it always has. At every idle it would be rough. Since the exhaust is so close to the frame where the slider plates were welded, I thought maybe that could be it but after glancing it over, everything looks the same.

Could the heat of the welding cause damage to the exhaust system? Also, would a cat converter issue cause a rough idle?

It seems to coincidental to have been running fine before, then to idle rough after.

Any suggestions would help

 

I always say that any time you weld on a frame, disconnect the battery, and the ECU. Welding can sometimes do some weird stuff. Perhaps disconnect the battery and allow the ECU to reset?

 

^^^^This not alot of people know this anytime your welding on your vehicle make sure you disconnect the battery

 

Yes they did have the battery disconnected. I'll disconnect again and see if that will help any thing. Thanks!

Any other recommendations are welcome

 

Just learning here please ~ How would welding affect things if the battery is still connected? I don't know enough to understand.

 

current will always take the path of least resistance

 

How long has then been going on, resetting the ECU will cause it to run rough and low idle for a bit but usually clears up after a few minutes.

 

I'm hoping this is the case. Before I disconnected the battery again, I started it up and took her for a spin and everything was fine, idles like normal. I'm guessing the ECU was ressetng itself when I first took off from the shop. Now all is good. Thanks for the help!

 

Welding uses very high current to create the weld pool. As mentioned it takes the path of least resistance of course, which is usually fine, but it is not uncommon for voltage spikes to occur, which can fry electronics. Disconnecting the battery and ECU fully prevents this from happening.

 

OOoooOooooo.....Okay I get it now. Thanks! Sorry being a newb..

 

Yup, lots of electricity can piss off your ECM. Always disconnect your battery when welding on or near your vehicle.

 

This.

Wife's Rav4 is horrible... takes a good 4 or 5 restart cycles before it's back to normal. First cycle, she has to keep her foot on the gas to keep it from dying.