92 Park Avenue rough idle/popping through exhaust

I have a 92 Park Avenue with approx. 240K miles,
It is idling rough like it wants to stall and it's popping through the exhaust. Any ideas what's causing this.
Thanks in advance,
Tony

Well, with 240K, it could be almost anything. When is the last time the timing chain was replaced?

It hasn't been replaced that I know of, I bought it with 107K miles,
I guess even with this many miles, it still goes down the road,

You should have some codes. Check what they are & post back.
service engine soon (http://www.geocities.com/dann8785/serviceenginesoon.html)

130k miles w/o a timing chain? That would do it...If the chain is stretched and loose enough, the engine wont fire right (timing would be off), causing the popping. BTW, this backfiring can potentially bend valve stems if the timing is off enough.

The help so far is on the right path. In my experience most popping through the exhaust is either timing or a very rich mixture. I would start by checking the fuel since it's the cheapest. My prime suspect would be a leaky injector if it turns out to be fuel related. A fuel pressure gauge will help but that will bring it down to either a leaky injector or check valve. My favorite is to simply raise the fuel rail and pressurize the system by turning the key on. Have a buddy watch the injectors for any leaks and you'll immediately know if it's related to an injector and if so, exactly which one.

If that passes getting a scantool will help diagnose any timing issues.

Good luck.