Hey guys,
9 days ago, me and my friends were having some fun in the fresh snow. I pulled my runner into a parking spot and threw her into reverse; she stalled out. Ever since then when I start her up she stalls right away. If I keep my foot on the gas she runs but with a nasty backfire. Before I swapped the EGR there was black smoke coming from the exhaust and a terrible gas smell during idle. I swapped the egr and maf and those symptoms stopped, I changed spark plugs and no improvment. I got a code 31 for vacuum switch, maf and egr, tomorrow I'm changing the ported vacuum switch and the plenum gasket... any other ideas if that doesn't work?

 

Please double check your post for bad auto corrects.

31 indicates a problem with the VAFM signal.

Symptoms indicate overfueling, stuck EGR, or possibly a trashed torque converter. Is it auto or manual?

Clear codes and start from there.

 

along with what year the engine is, what the engine is, etc. we cannot see your truck. in order for people to help you, you need to let them know what you have and what you are looking at.