Help!! P0302
Help!! P0302
I was driving along this morning when all of sudden I got a cell..I pull out my pocket scanner and it tells me that I have a P0302..it reads it as a misfire and also mentions something about O2 sensor..I was wondering has anyone else had this problem..also..if I do have a bad o2 sensor which one is it?
Account Disabled
Joined: Jan 2007
Posts: 160
Likes: 2
From: SLC, UT
P0302 is a misfire on cylinder 2, the 2nd cylinder from the timing chain side. Check the coilpack and plug. Then check the fuel injector for correct resistance across the coil. Lastly, check compression.
also, try swapping the 2nd injector to a different cylinder just to see if that code appears on a different cylinder instead. and if it still occured then do a "leak down test" to make sure ur valve seals are good and no issue there. gl
I just got this code on my Evo IX although it told me it was a misfire on cylinder 1 so iono. I plan to check the spark plugs first and make sure they're all good and basically follow them back to the wires and coil packs. The fuel injectors should not be the culprit. Your O2 sensor could be bad too.
Basically you and myself are probably running richer than we should and thus are fouling plugs. That's the gist of it anyways.
Basically you and myself are probably running richer than we should and thus are fouling plugs. That's the gist of it anyways.
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Evolved Member
Joined: May 2003
Posts: 2,815
Likes: 24
From: Davidson, NC
I'm guessing it's related to this:
So, was it the fuel pump fuse you tapped and the gauge wiring was shorting it out? It's a little unclear.
Ok, so I stopped into AMS yesterday to get a custom flash. After a few minutes they informed me that my car couldn't take the tune because it was running to lean. They did me a huge favor "which I'm super grateful for" in finding out that the fuel pump doesn't change voltage when the car is at full throttle, hence running too lean. The AFR is at 14 and that was pulsing the injectors 100% at the stock map again. They didn't have a full service manual to tell them what exactly controls the voltage on the fuel pump. Has anyone had this problem besides me!? 
I am really at a loss.
My mods so far are AMS FMIC, UICP and base flash. I also have a UR full turbo back with test pipe and cone filter. I really need to find out how to get more fuel to the engine..I don't want to blow it..On another not I did notice that since I'm back on the stock map the car isn't pulling timing like it was before I brought it in..This is going to make it hard to convince the dealer that there is something wrong with the fuel system..I really need to know what controls that..or what tells the fuel pump to dump more fuel..
I am really at a loss. My mods so far are AMS FMIC, UICP and base flash. I also have a UR full turbo back with test pipe and cone filter. I really need to find out how to get more fuel to the engine..I don't want to blow it..On another not I did notice that since I'm back on the stock map the car isn't pulling timing like it was before I brought it in..This is going to make it hard to convince the dealer that there is something wrong with the fuel system..I really need to know what controls that..or what tells the fuel pump to dump more fuel..
PROBLEM SOLVED
...so I decided to ohm out all the relays to see if they were bad..I pulled every single one....one by one of course..lol..and they all were good..so I am thinking..wtf.. Then I decided to take a look at my boost gauge. For power I wrapped wire around a fuse and stuck it inside of the fuse panel in the passenger compartment. I checked the hot lead and the ground...bingo there it was.. the ground was grounding out on something..the wire was hanging..but touching another wire...to top it off the wire for some reason was a bit frayed. So I tighten everything back up and put it in it's place..took the car for a spin..and bada bing bada boom..car is pulling like no tomorrow..well..for what can be expected on the stock fuel map..but everything is ok...
THANKS GUYS FOR ALL YOUR HELP!!!!!!
...so I decided to ohm out all the relays to see if they were bad..I pulled every single one....one by one of course..lol..and they all were good..so I am thinking..wtf.. Then I decided to take a look at my boost gauge. For power I wrapped wire around a fuse and stuck it inside of the fuse panel in the passenger compartment. I checked the hot lead and the ground...bingo there it was.. the ground was grounding out on something..the wire was hanging..but touching another wire...to top it off the wire for some reason was a bit frayed. So I tighten everything back up and put it in it's place..took the car for a spin..and bada bing bada boom..car is pulling like no tomorrow..well..for what can be expected on the stock fuel map..but everything is ok...THANKS GUYS FOR ALL YOUR HELP!!!!!!
I haven't heard of this issue. Is it a common problem on a stock fuel pump? Walbro 255lph as well? If this is any lesson, it's to be sure that you always have a working wideband to monitor your AFR's with.
Newbie
Joined: Apr 2009
Posts: 75
Likes: 0
From: Milwaukee,WI
My mods so far are AMS FMIC, UICP and base flash. I also have a UR full turbo back with test pipe and cone filter.
How could these mods cause it to run so lean is it because of the base flash?? Cause with just the mods and NO flash wouldn't the car still be running in the 10's or 11's AFR????
just an fyi, on my ix after i put the 3'' tbe without the flash i started noticing boost creep around 5k rpm, not sure if this information coudl u to anything.
the turbo will definitly breath alot better with the exhaust.
the turbo will definitly breath alot better with the exhaust.
Evolved Member
Joined: May 2003
Posts: 2,815
Likes: 24
From: Davidson, NC
My mods so far are AMS FMIC, UICP and base flash. I also have a UR full turbo back with test pipe and cone filter.
How could these mods cause it to run so lean is it because of the base flash?? Cause with just the mods and NO flash wouldn't the car still be running in the 10's or 11's AFR????
How could these mods cause it to run so lean is it because of the base flash?? Cause with just the mods and NO flash wouldn't the car still be running in the 10's or 11's AFR????
Last edited by hotrod2448; May 27, 2009 at 10:22 AM.