gmv93

hello friends, i've sold my bmw and bought 2004 make jeep liberty. zj and kj are friends now both are px8 black color and almost factory stock. kj is on50000 miles, running on bifuel Propane setup like our Zj does.

here is situation. check engine is intermittently come on and goes. freeze frame data shows p0171 dtc. it is bank 1 is lean. which means v6 bank 1, passenger side of v block. no p0174 code.

then i faced stalling problems. i read much about similar problems and decided to check sensors valves etc. i found that engine oil was excessive previously and oil vapors caused dust collection on MAP sensor on intake, throttle position sensor, idle ontroller and PCV valve. i cleaned all and i alse cleaned thottle by removing it, i replaced sparkplugs which seemed used in a prolonged period.

i reset the ecu and car started idled and accelerated like new! no stalling no rough idling. at that moment there was no cel on situation but a freeed code in memory. now, after reset i did 3 warmups,100 miles in total, cell is on again with abolutely no drivability problems. code is again same p0171.

i suspect three things . vacuum leak at pcv hoses or on intake gasket at bank 1, pre o2 sensor is going bad or ecu is going bad. no idea about exhast leaks before sensor.

any insight? can i do smoke test to find a leak? i sprayed pad cleaner to engine block engine sound did not change. can i interchange pre o2 sensors with eachother?

JeepingDan

If you have access to a smoke tester then by all means it would not hurt to use it.
Not mocking but chrysler rubber products deteriorate pretty quickly. I've replaced a lot of PVC plumbing on dodge and jeep.

gmv93

i will try to find cracked or split PCV hoses first then i will use smoke test methods.

there is absolutely no drivability problems. this is due to my dual fuel setup.. may be.

gmv93

I checked every pcv hose i can reach i, un plugged them i plugged them i coudl not find a crack or split hose. evaporation related can is hissing, i am not sure if it is normal but there is no hose related leaks i guess. do you have any idea about that canister with a electrical connector on it? it is attached to right side of radiator (not filter box side)

any comments?

what is idle speed for 3.7 engine when it is warm and neutral. it idles around 950 rpm which seems quite high to me. is there an adaptation process by dealer?

o2 sensors are both working at same voltage switching rate and they are operational.

i even tried with brake pad cleaner spray on engine, and i even tried propane torch trick to see if idle changes, nothing happened.

gmv93

my video clip for idle problem.

gmv93

today i unplugged and plugged big connectors from main control unit located on driver side fender. i have a scangauge eco, i was checking TPS percentage it was showing 16. which is actually equal to 2000 rpm. i dsconncted big connector it triggered major codes. engine was off ignition was on. i plugged back everything and reset. tps showed 11 percent ! i drove in heavvy traffic absolutely no problem. i suspect that there is an oxidation problem on sockets.