2002 neon. When I come to a stop, the engine pings and sounds like a diesel engine, sometimes cuts off. No check engine light. I replaced the timing belt, coil pack sensor, plugs and wires. power steering switch, IAC motor, TPS sensor, both O2 sensors. And it didn't fix the problem. It does burn about a quart of oil every 3 weeks...I took it to a shop and they said the catalytic converter was clogged, I replaced it, and still have the same problem, can the muffler be clogged too? I heard there may be a PCM flash for this problem, but its for a rough idle, i have bad dieseling pinging and rough idle. Any help is appreciated! Ive spent $1500 so far, Im ready to go to the Dealer next.

 

Buy a compression tester:
http://www.amazon.com/Actron-CP7828-.../dp/B00020BM28

When you get it screw the tester in a sparkplug hole and crank the engine over for about 5 seconds.
Check the reading.

If all 4 cylinders are between 125 and 160 PSI and are at least 5% of eachother you can rule out an engine overhaul. If not... well you can see where I'm going with this.

 

With all sorts of problems, and large oil consumption, a compression test wouldn't be a bad place to start to see if the engine itself is gone or not. Though, no check engine lights but a clogged cat? Interesting...

 

After reading all that my first thought was that the piston rings are gone. then a possible rod knocking.

 

Thanks both of you!!!! i will check cylinder compression next or do the cylinder leak down test

 

Yup! That's where I was going with it.