I have gotten a lot of help from a lot of people on here in my original thread (http://www.jeepforum.com/forum/f310/...-help-1490914/
), but I still have the issue. I wanted to start a new thread as my original one has 26 pages going...and I want to get something cleaner going with some compiled info. Any help is greatly appreciated. So here is my breakdown. 2004 JGC 8cyl 4.7 NON ho Symptoms; Getting anywhere from 6mpg (winter blend) to 10mpg around town, around 18 highway...When I first got the Jeep 2+ years ago, I was getting 13 around town. Easy 20 highway. All calculated by hand, no EVIC. About 4 months later the issue started. Rough idle, will surge/slight stumble (not a lot) when idle from time to time. Maybe once every 3-4 weeks the Jeep will stumble and stall or just shut off completely. Starts right back up. Starting the Jeep takes about 4 seconds, cranks about 4 times before it starts. Mode 6 fails, TID 11, 31 both o2 half cycle counts and 51 purge monitor IAC shift, sometimes 52 purge monitor adaptive fuel shift, 53 purge monitor rpm shift, 61 & 62 both leak detection pump period. I was told my purge solenoid is overactive, but no one can tell me why. I have a constant air intake type "whistle", throttle position sensor shows 10.6 -11% key on and same when idle. Slight exhaust/gas smell at startup Downstream o2s look lazy from time to time. I get some clunky transmission action here and there. Like a weird downshift or upshift when around the shift points, around town. Not highway. NO CEL or stored codes.
Add to the list a hard start. Went to start, few seconds and it didn't catch, waited a few seconds went to start and it wouldn't catch. Third time it started but sounded like it was lacking fuel
What has been done since the issue started Cruise control works no problem. All 8 plugs, champion copper Air filter TB cleaning, took it off, cleaned it, cleaned what I could reach in intake. Seafoam through the TB, blew out a lot of black, now if I seafoam exhaust comes out clean. All 8 coils Fuel pump, mopar Fuel pressure is correct and holds Thermostat Map sensor is working properly TPS Mopar IAC Mopar All 4 o2's Mopars downstream, last year, Mopar upstream last month. Exhaust manifold gasket to fix leak New cats and exhaust high flow 3" I've checked grounds in engine compartment, all reading within 1/2v of the battery. Jiggled all harnesses, no change. Pulled PCM connectors, appeared fine, reattached Coolant system was pressure tested. Banged the pcm thinking maybe there was a short or something, no change. I've heard of pcms needing a reflash for o2 and driving issues, but only found a tsb on 4.0 I have disconnected the battery for x amount of time to reset after most changes. Sprayed every line I could find with TB cleaner, no RPM shifts. That's all I can think of at the moment. Thanks in advance Also upgraded 136a alternator to a 160amp. My stereos pushing 1k+ watts so I figured it would do some good.