Jeep throwing codes like crazy

Ok I bought her first week of May. First day I had ground issue with headlight, no problem, easy fix. Drive her to a concert 30 miles away she threw code P0303 (reset computer by disconnecting battery and she did fine rest of night) next day, same code. Replaced all spark plugs. Still throws it. Replaced coil pack. Swapped injectors around (3 to 6) threw p0304. Reset computer. And she still skips at low speeds or idle but at 55 she does fine. She did throw a camshaft position sensor and I replaced it and the crank shaft sensor on the way to the beach (3 and a half hours away) did perfect at beach til day 4 and she threw code P0303... misfire in three again. So now we are back to that. Any suggestions on where to go now??

 

lets try this - get a SCAN done on the jeep - free at many auto part stores. post all codes.

Let us know -
Any modifications to powertrain?
the spark plugs you used were? brand does matter...
this is a 2004 wrangler - 4.0L eng and a manual or automatic?

How comfortable are you with - tools, test gauges, wiring?
Do you have a good scanner able to see live data, I know but I can hope.

 

A bluetooth OBD2 dongle and an app for your smart phone are a wise investment.
Not only can it read codes and show you live data it can also clear the codes without having to disconnect the battery.

 

I guess I should have went into all that. She’s a 4.0 manual 4x4. I bought her cause she hadn’t been modified at all. I want to do that. I did put in Motorcraft spark plugs from Advance Auto. Also checked the gap just to be sure. I have a scanner from snap on but for some reason it’s not letting me get a read from her even though it will on my F250. As far as comfort with tools and test gauges and volt meters I’m pretty comfortable. Wiring only thing I’ve ever done on my own was run a pre made wiring harness.

 

Prerunner82 smart suggestion. Thanks. I’ve not thought about getting one

 

Codes she’s throwing 0303, 0304, 0340, 1391, 0352, p353

 

Are these still the current active codes on the vehicle since you last cleared it?

 

Not after I clear them. They will go away. She will drive fine for about 40-50 miles unless I’m in slow traffic. Slow speeds throw misfire on 3 within minutes.

 

I meant are those the codes currently on the vehicle right now?

 

303 on a regular basis

 

the snap on not communicating, my first thought is confirm 12v at cavity 16 of DLC.

Plugs I asked this coil rail does NOT like platinum or other 'fancy' plugs just a solid core- lucky for us the inexpensive will do.

The misfire codes AND I see a coil codes.
MIsfires are spark, fuel or mechanical. As I suggest a plan, start with adding a can of 'seafoam' fuel detergent.
>> there is a harness issue at the rear of cyl head, harness rubs thru on stud. more later. Check harness rear of head at valve cover as it goes over head bolt for evidence of chaffing I will try to get a diagram.....

The 2 sensor codes p0340 and p1391. time ran out GTG follow up later

 

Thank you. I will try the seafoam. Tried basic cleaner when it first happened but will try this now. The 0340 and the 1391 did register together.

 

Update! Used the seafoam, no change. Bought a BlueDriver obd reader, still no help. After being told someone had cleaned the grounds already I decided I would go behind them and clean them. (They had been taken off but had lots of gunk on them)Cleaned them my way and guess what!?! She’s ran perfect since then! From now on no one touches her unless I’m there! Lol