I drove my 1995 Jeep Cherokee XJ 2WD the other day and I heard two loud pops. I’m not sure if it was gunfire, another vehicle around me or
my jeep. It was loud and felt like it was close by. My jeep didn’t do anything out of the normal. I was slowing down at this time getting off the interstate from 70 mph to 60 mph.

I also had another time when I heard a loud pop more into town and I was not on the gas but was slowing down/coasting on a downhill slope.

both times I can hear the sound echo off into the distance. I’ve been driving 30-45 minutes.

I did drive it today but it wasn’t a long drive today and didn’t hear any noises.

could it be shots I heard or is my jeep backfiring? If it is backfiring what can I do to fix it?

 

It's probably not a backfire. It's probably an afterfire. Not a commonly used term, I know. But there's a difference. If it's afterfire, it's from excess fuel in the exhaust suddenly getting very hot. I'd suspect the TPS is telling the ECU that the throttle isn't fully shut, or the MAP sensor is a little off. If either of them aren't telling the ECU that it's time to cut fuel (during a hard decel) then you'll get afterfires... which are super cool looking, but can be damaging.

 

Civilians call it that because it is "fire from the back end", but after fire is technically correct. Kudos to agreen for knowing and helping guide the discussion for more accurate diagnosis. Back would be backward through the engine shooting out of the intake.

But, yes, it can cause a problem, especially with cars that have a catalytic converter. That fine ceramic honeycomb in there is not bullet proof. It doesn't usually hurt immediately, but you don't really want to risk leaving it unfixed, especially if it is loud enough to echo and be mistaken for gunshots.

agreen gives a good first few things to check, so really I'm just posting a +1 to look in to it.

 

Alright. I’m going to do one more drive on the same road and see if it does it again. It’s odd I don’t hear it on the way back home. Ill definitely get it fixed right away if it happens again.

 

got many enemies, been cutting someone elses lawn ?

 

Naww man. It’s just the neighborhood(city) I’ve been through isn’t the greatest.

 

Fully up to temp and how much negative load (engine braking) can have a big effect on whether it does this or not, so that might explain the one way but not the other bit. Hills and timing and such...

I used to hear gunshots in Detroit just about every time I was there.

 

I replaced the MAP sensor and drove it a few times last week and this week. I haven't heard any backfiring noises so far. I was going to change the other sensor, but it's pretty snug and I didn't want to strip it.