I have an 08 JK with the 3.8. After getting up to normal temp the engine will ping when accelerating. Not running hot been same exact temp for last 3 years. Tried different fuel even premium with no change. In last 2 months I have changed the plugs and the following sensors- crankshaft, camshaft, anti knock, map and all 4 02 sensors. Any suggestions? Maybe injectors?? TIA

 

Sounds like carbon in the cylinder that heats up and causes pre-ignition. Probably won't occur until full temps are reached. To fix it, if it is carbon buildup, requires an application of cylinder cleaner like Seafoam then followed by a good thrashing and I mean a valve bouncing (almost) good hiding through the gears - 5000rpm or better in each gear. To do the job you run it to full temperature then head to a parking spot in a place near a highway you can thrash the Jeep on straight away IE no town driving is best. You have a friend help you and seeing as you do not have a Mass Airflow Sensor you can simply remove the air cleaner lid and the element. Run the engine and maintain 1500-2000rpm and spray the entire can of cleaner in there. Once it is all done turn the engine off and sit around for about 15-20 minutes., Then start it up and thrash it down the highway. Come back home and preferably let it sit all night till next morning. Bet it will be a lot better.
Just to advise - I was a bit lacking in doing this to my direct injected Chevvy engine in my Jeep until a week ago. It would not go over 4000RPM but still had good power up to that. When I did the Seafoam thing and ran it she let out such a cloud of black smoke that it sat around for as far back I could see. Cars had to file Instrument Flight Rules to navigate through but the highway thrashing yielded a lot more power and RPM running 1/2/3/4 (have 8) up to 90mph in 4th she cleaned out and boy does it go now and way less ticks from the engine (DI is noisy). I should do it every 6-8000miles but was a bit slow hence the big Italian tune. But the stuff works!

 

I agree it's probably carbon buildup. Seafoam works great to help clean it out.

I haven't had a carbon buildup issue in years. Don't know if I'm just lucky, but there are two things I like to do with my vehicles to prevent carbon buildup.

First is to use a good-quality gasoline. I'm not a fan of additives that can be added to your tank, though some swear by them. A "Top Tier" gasoline should have enough additives to help prevent carbon buildup. I often cheap out and use unbranded gasoline, but I make sure to use a Top Tier brand when I can. FCA (or Stellantis if you prefer) actually recommends using only Top Tier gasoline in more recent owner's manuals. You can search online for brands that are Top Tier.

Second, don't be afraid to do an "Italian tune up" every now and then. Getting the engine up to almost redline helps by getting the engine hot enough to burn out any deposits. This works best if there is a load on the engine, like going up a hill. Be aware of traffic and especially of Officer Friendly when you do that! We have plenty of long grades in AZ and I take the opportunity to slow down a bit at the bottom and floor it going up - until I hit the speed limit of course! Shouldn't need to do it often, but maybe once a month or so should be enough.

As the saying goes, an ounce of prevention is worth a pound of Seafoam! ...or something like that.

 

Allow a recommendation .. Years ago (can't disclose where/what automotive engineering group) endorsed Chevron Techron Fuel System Cleaner.. To this day (over 30 years) I periodically put a bottle in a full tank on all my Jeeps. I buy in 6 bottle packs from AZ. Especially if I have run mucho Cheapo Gas..