1994 Chevy 4.3L backfire
Hey— so I got this 1994 Chevy c1500 4.3L a little over a year ago for a going to town driver. Drove it about 1k miles before I had to put a fuel pump on it. It ran pretty good. Just slow, a little hesitation, and drank up gas.
Decided to check the plugs and wires while tuning it up. I noticed one wire was completely off of cylinder 6. Replaced the plugs with Delco brand but they looked good. It didn’t have a muffler on it when I bought so I dropped it off at the shop and got one on.
I drove it home from the shop and it backfired and blew the muffler. It ran sluggish too.
Since then, I’ve put a new ICM, MAP sensor, knock sensor was disconnected so I plugged it in, new cap, IAC valve, and cleaned the throttle body.
It’s running better. Much quicker and more efficient. But…I still have the backfire.
I don’t believe I have a vacuum leak from anything visible on the front. What else am I missing?