Very Rough Idle

[JacksonH]

So I have a 2000 with i6 and automatic transmission. I had a low idle/stalling issue for about a year now and I’ve replaced a lot of different sensors and parts that deal with controlling the idle but none of them have seem to fixed the issue.
I’ve replaced the TPS, MAP, Upstream O2, and Cleaned the IAC and throttle body several times. (I reset the computer each time). I would run great for about 30mins and then the idle would go back to how it originally was (rough). I think it might be my IAC because when I unplugged it and plug it back in I see no change in idle. It also could be a transmission issue since every time I put my car into reverse from park the idle drops when I stop.
Any ideas on what might be the problem?

 

[RMETeeJay]

Do you have any stored OBDII codes?

If you haven't yet thrown them away, hold on to your Mopar sensors & parts. They may be perfectly fine.

Do a vacuum leak test on the intake and exhaust: https://wranglertjforum.com/threads/cheap-engine-vacuum-leak-tester.19643/

 

[JacksonH]

Do you have any stored OBDII codes?

If you haven't yet thrown them away, hold on to your Mopar sensors & parts. They may be perfectly fine.

Do a vacuum leak test on the intake and exhaust: https://wranglertjforum.com/threads/cheap-engine-vacuum-leak-tester.19643/

I don’t have any codes. But I do have an OBDII reader coming in the mail.
I’ve also kept all my old parts except the O2 sensor.

 

[RMETeeJay]

If the behavior didn't change after the new IAC, I'd put the original Mopar back in if you got another brand. With it already out, you can clean the plunger thoroughly beforehand and the TB opening it goes into.

Is your ATF level correct? You might as well rule that out. It's important to check it the way shown here: https://wranglertjforum.com/threads...our-30rh-32rh-or-42rle-jeep-wrangler-tj.7901/

 

[JacksonH]

If the behavior didn't change after the new IAC, I'd put the original Mopar back in if you got another brand. With it already out, you can clean the plunger thoroughly beforehand and the TB opening it goes into.

Is your ATF level correct? You might as well rule that out. It's important to check it the way shown here: https://wranglertjforum.com/threads...our-30rh-32rh-or-42rle-jeep-wrangler-tj.7901/

I still have the factory IAC in my Jeep and my ATF fluid is a little below full but not to low, but I have plans a change the fluid and possibly adding an additional cooler since I live in the mountains and drive up hill a lot.