CEL p0300 ?

[Gravedigger]

Multiple miss fir e code.

Would any of ya
ll have some infor on what all to replace.I have replaced the coil and up stream/down stream O2 sensors a couple weeks ago.

Would a good ol fashioned tune up do the trick.

recommendations on spark plugs cap rotor and wires from any local auto parts stores such as O'Reilly Autozone or Napa.

Online

Jeep feels hoo

[4.3LXJ]

I would start there

[Gravedigger]

Went with a full tune up.(96 cherokee country)
i will need new tags in a couple months and DEQ is never fun
I cleared the CEL code so in 50 starts of the jeep i will see if this did the trick.
what i have done so far the past couple weeks to curb this issue,part numbers will follow the part.

cap,rotor,plug wires,spark plugs came from Napa.the coil came from o'rieleys.the o2 sensors came from rockauto.

new up stream o2 sensor-NTK 23121
new down stream o2 sensor-NTK 23014
new coil-(BWD)Part # E64
new rotor- ech MO31
new cap- ech MO30
new plug wires- Belden 700444
new plugs-champion 412 copper
2 cans of sea-foam on a full tank with regular gas.
Mobil 1 extend performance M1-301 oil filter(over size filter, thanks for the info on that handy upgrade)
Mobil 1 extended performance synthetic oil.

I am big fan of Mobil1......just thought i would toss that out there.

[Gravedigger]

just got hit with p0303.

cyl# 3

i think i will just get another plug and replace #3.may have been a faulty plug....i hope

[sidewaysstarion]

just got hit with p0303.

cyl# 3

i think i will just get another plug and replace #3.may have been a faulty plug....i hope

Well you need 3 things for an engine to run, fuel, compression and spark. Since you've ruled out spark, Assuming it sound normal when its cranking over. I'd start looking at fueling. Since the issue seems to be on #3 I'd check the wiring to the #3 injector and make sure the injector looks ok. I had a jeep that had an intermittent P0303 and it turns out the #3 injector harness was pinched under the throttle cable bracket and shorting out randomly causing the miss.

If the wiring and the injector look good and you replace the plug, I'd try swapping the #3 and #4 injectors around and see if the misfire follows the injector or stays the same.

[Gravedigger]

i will try swapping the injectors.

i did clean the tps,iac, and replace the #3 plug.