DTC codes, vehicle running rough

So, today I went for a little drive in the jeep. While going at slow speeds, around 45 mph, I noticed it was running really rough and thought it was getting ready to stall. Luckily I was about to get back to house and used my scanner and got the following codes:

P0171 - Fuel system 1/1 Lean
P0174 - Fuel system 2/1 Lean
P0307 - cylinder 7 misfire
P2096 - Downstream fuel trim system 1 lean
P2099 - Downstream fuel trim system 2 Rich

First thing I did was check my plugs. They were awful. I replaced all my plugs and that seemed to clear the P0307, P2096 and P2099. Well at least they haven't came back yet.

After replacing the plugs, I took it for a drive. After about 20 mins, and driving slow 45 - 50 mph the vehicle started running rough and felt as if it was going to stall. When I checked the codes again, the codes present were the P0171 and P0174.

I checked my fuel pressure and had 56 psi.

Umm, not really sure if I am looking at a fuel pump problem or an exhaust leak. The only reason why I mention the exhaust leak is I have a leak at one of my exhaust manifolds. You can hear the ticking sound.

Any suggestions?

Thanks

Your fuel pressure is on the low end of the tolerance but definitely not bad.

What flashpack tune and fuel grade are you using?

91 performance and I run 93 octane

I'd return it to stock, disconnect the battery and run a tank or two of regular through it just to rule out any issues with messing with fuel tables.

Thanks for the idea Matt. So what I did this morning was return it back to stock tune. I rechecked the fuel pressure with the vehicle running this time and got 59 psi. The previous reading was with the ignition set to run. I have taken it for a couple test runs, interstate and country roads varying speeds from 45 up to 80. No codes have reappeared and I'm getting a lot better gas milage. Before with the tune installed I average 11 and 12 mpg, with stock tune it jumped up to 15 and 16 mpg. Only time will tell though. The plugs I removed were the worst I've ever seen, they have only been installed for about 30,000 miles. I'm wondering if running the 91 performance tune caused all my plugs to foul. If anything changes, I will keep everyone informed. Thanks for the help.

Hmmm I have an 07 4.7 liter and just hit 150,000 miles today. I have been running the 91 performance tune for well over 3 years with either 91 or 93 octane gas and haven't had any issues! What plugs do you use. I've found out that the OEM champions work best for my jeep. I'm getting almost 13 mpg city and I'm running 305/70R17's. This weekend on a 6 hour drive to play Army I got up to 16.8 mpg with cruise set to 65 mph.

I was using the OEM ones. It was just wierd how fouled they were. Don't really understand why. Only thing I could think of is because of the tune. I will drive around on the stock tune for a while and keep checking them.

How long have you been running the tune?

Right around 4 years now.

So why would it just start running bad and getting codes if you have been running that tune for 4 years

I did some research for you about tunes and gas etc... This is common for people who use low grade gas or not high enough octane for the tune. Not saying thats what you did but these symptoms are.. What gas station are you using? Are you sure the tune was for the 91 tune? It was only a short period of time but I ran the diablo intune 91 tune and had no issues and when i checked my plugs they were damn near perfect. I only ran Sunoco or Mobil and beat the piss out of the HEMI to be honest..

Yea it could be just bad gas. (Insert immature snicker here)

I put some bad gas in my Toyota truck I had one time. It had a lot of water in the gas. Truck would sputter real bad. Some old timers said to run a bottle of rubbing alcohol through my tank along with the bad gas. The rubbing alcohol would help dry up the water in the gas. I did it and it actually helped it run better, no spitting and sputtering.

It's a possibility of being bad gas. I try to stay away of the cheaper stations like elcheapo and enmark. Mostly chevron, BP and shell are the stations I goto in my area. But anyways I simply stated I wasn't really sure of what could have been the cause, the only thing that came to mind was the tune. Whether or not that was the cause it just bugs me that I had a problem. On a side note, I was poking around under neath the jeep while the wife was giving it some gas and noticed I do have a bad exhaust manifold leak on the drivers side. So tonight I decided to tackle taking everything apart and getting it prepped for a new gasket and hardware. Well, 3 of the bolts that secure the manifold on plus help secure the heat shield in place are broken off in the head. Again I appreciate all help.

I had the same issue. I welded a nut on the ends of the snapped off studs after removing the manifold and then used a socket to get the studs out. Easy fix if you have access to a welder. If not try to use vice grips or an easy out drill bit

Make sure to have the manifold checked, or you'll most likely be doing the job over in six months like I did ;)

Yeah mine was warped, replaced the manifold while I was at it!