Haughernaut

So I was given a ZJ 4.0 L6 from my parents that had a little over 190k on it and I've now pushed it past 200k.

I'm having some problems with it now that started right around 199,800. Right now, the engine is having problems where it will lose RPM or stall when I depress the gas pedal when coming to a stop. I did some minor searches on this it read to me like it might be a problem with the TPS, which would just need some cleaning and some oil(Making sure to not damage the gaskets).

The idle is also a little rough and it kind of sounds like there might be a misfire or two. I was thinking of replacing all the spark plugs this week.

The catalytic converter was stolen as it left parked for weeks at time in the middle of no where on a mountain side. Right now, the tail pipe is just a straight pipe all the way through because the CC was never replaced. Therefore, there is no O2 sensor installed at all.

dave1123

The rear 02 sensor doesn't matter much. What about the primary 02 in the manifold downpipe? That one is important because the PCM reads it and adjusts the mixtures accordingly.

Thexjfiles

You can clean the IAC, but not the TPS.