Heya all,
Need advice please. I have a Neon 2001 2L 16V manual transmision.

Problems:
Irregular idling, huge loss of power, emitting black smoke [ unburned fuel ]

Have done so far:
Removed CAT
Checked coil
Changed plugs twice

Other info:
I get different answers from different Mechanics/Workshops:
- ecu faulty
- lamda sensors faulty
- crank sensor faulty

Previously I had the ecu reset via diagnostic tools, the car performed well for a month, then back to black smoke again. Went back to diagnostic place, did not get error code from ecu. This morning I tried the reset myself by removing car battery terminal for 10mins. The car is a lot better, but will gradually deteriorate over a period of 3 to 4 weeks.

It seems whatever the problem is, manifests itself over time after the ECU gets reset.

Any suggestions please?

 

Well, the cat helps burn up a/f that isn't burned in the engine.

If you keep having to reset the computer, sounds to me like that could be the problem?

 

if resetting the computer is clearing it up for a few weeks, that does sound like the computer.... BUT could it also be that reseting the computer is clearing the codes, but yet after 3 to 4 weeks of running, the sensors are throwing codes again while the computer is trying to correct the problems it making it run like ****, then you reset it again? I couldnt really tell you about this, your prolly better off taking it to a dodge dealer... did you try running diagnostics on it with an OBDII or the key switch trick?

 

Not sure which type diagnostic equipment were/are used. Had it to Bosch once, they advised LAMDA sensors. Key switch trick?.. please elaborate.

 

Whoa...Too many sucking problems...lol

 

turn the key on and off 2 times then hold the trip button and turn it on and leave it on, your gauges will jump in quarters and it will start showing you codes.... *if there are in codes to show of course* i truly dont think the computer is the problem cause it will run fine if you reset it, i think its some bad sensors.

 

Thanks for the replies, it helps. My gut also tells me it is bad sensors, I am sure the ECU does constant correcting and at some point the RAM gets full.
Will try the key trick.
I will start with the LAMDA sensors and work from there on.