Now to figure out this missing problem

[97blueyuk]

Okay so I just did a fuel pump. Now time to look at the miss issue. I already did a cap and rotor, wires and plugs look good. Sprayed the engine area with brakekleen to check for vacuum leaks found nothing.

Idle is about 700 and rough, during acceleration it is very rough. Check engine light flashes while accelerating (does stop flashing when coasting/cruising). I had the codes read before the cap/rotor and they were


p0125 p0141 p0155 p0300 p0430 p0141 p0306 (i had the batt disconnected for a few days and cel light came on after about 30 mins run time, did not have it rescanned)

it feels alot like when the cats went bad on my expedition. could the cat solve the issues?

 

[Kenric]

In case you need them decoded.


P0125 = Engine Coolant Temperature (ECT) Insufficient for Closed Loop Fuel Control

P0141 = O2S Heater Performance Bank 1 Sensor 2

P0155 = O2S Heater Performance Bank 2 Sensor 1

P0300 = Engine Misfire Detected

P0430 = Catalyst System Low Efficiency Bank 2

P0306 = Cylinder 6 Misfire Detected

 

[retorq]

Wires can look good and be bad.

 

[SunlitComet]

please rescan the pcm and while you are at it ensure you did not break any grounds on the thermostat housing. also remove and inspect the pcm connector labelled blue for dirty contacts. and the coolant sensor on the thermostat housing as well.

 

[97blueyuk]

is there a way to get the codes without a scanner? I remember my 03 durango you could just cycle the ignition a few time and get the codes.

 

[97blueyuk]

just got back from getting it scanned. only codes were
p0155 02 sensor
p0300 random cylinder misfire

should i consider an o2 sensor?

 

[SunlitComet]

yes that code is for the right bank primary o2 sensor. even tho it is a heater circuit issue the sensor has the primary role of affecting the a/f ratio for that cylinder head. depending on how bad it is it might improve things where the misfire might clear it self out one a stable nominal ration is achieved.

 

[97blueyuk]

ordered the new 02 sensor should be here tuesday. will see what happens.

 

[SunlitComet]

should have mentioned delphi or acdelco unit only.

 

[97blueyuk]

got the delco unit.

 

[99Yukon4x4]

My '99 Yukon had the same misfire issues. Once the check engine light came on, I had it scanned and found my #4 plug was bad (after I had replaced them 7 months before). It also had oil deposits on it. I normally pull the plug once a month and clean it up, and it runs fine.

NOTE- Body had 191K on it, but the engine is not original. Not sure what year, or what it came from. Other than that issue, drove it from Tampa Florida to Philadelphia loaded, and handled fine, and still got 17mpg on it.

 

[97blueyuk]

changed the o2 sensor, cleared the codes, the 0300 came back a few mins later. let it run a lil bit (but did not drive) and the cel went out. checked the codes again and nothing. still runs a lil rough though, i will take it for a ride later and see how it goes.

thanks for everyones help