Sounds alot like my truck. Starts & idles fine, then at about 2 minutes starts chugging & coughing. Doesn't quite die. If I hit the gas it revs right up and sounds fine and usually clears up after a bit.

My plugs, wires, cap & rotors are all pretty new. I've still got a bunch of stuff to investigate. I haven't checked the plenum on mine yet, but my pre-cat O2 sensor threw a code the other day for rich fuel mixture.

 

Yup, thats exactly my issue. I bet your exhaust smells horrible while the chugging is happening too right?

I never had any codes, I replaced the O2 just on HeyYou's advice. it defiantly needed to be changed even if it wasn't the root of the issue, the old one was just caked black.

Im gonna make it drink a load of seafoam later, see if that helps.. *shrug*

 

that sounds exactly like what my truck was doing a couple months ago.. i went through everything and replaced every sensor and it was still doing it. i finally figured out that it was only a bad fuse in the fusebox under the hood that i missed.. have you checked all of your fuses??

 

No, I haven't actually....

Which fuse was it?

 

Yup bad combustion smell, coughed up chunks in the snow. Maybe my cat is junk.

I tried the seafoam. Didn't hurt, but didn't help either...

 

I'm gonna do an entire damn can down the brake booster.... i figure it will either blow something up, or fix the issue.....quite frankly don't care at this point

 

its the first small 15 amp fuse in the fusebox under the hood, the fuse closest to the drivers side fender. theres a diagram on the inside of the fusebox cover, its the 15 amp o2 sensor fuse. i took the 15 amp fuse out of the spot marked security (dont know what its for, my truck doesn't have an alarm) and put it in the o2 sensor fuse spot and it was good as new.

 

Will check later...if your right and this whole time a FUSE has been my problem.......I think im going to eat my bumper.

 

lmao! yea thats basically how i felt after i found out it was just the fuse.. i was driving myself crazy trying to find the problem, not to mention all the money i wasted on parts i didnt need..

 

Checked the O2 sensor fuse in mine and it was good. I did notice some corrosion in the fuse terminal. I used my multimeter to check continuity on the terminal with the fuse disconnected. With the negative battery terminal disconnected, it gave me one short beep and gave me a reading of .6-ish.
With the battery connected, continuity did not beep but gave me a reading of 1.7-ish.

The same check on other fuses gave no beeps and 0.0 reading on the meter.

I've gotta check what those readings mean, but I wonder if there's a bad ground or intermittent short on that circuit.