97 expy 4.6 p0304 code

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Apr 22, 2012 | 11:50 AM

vics97xlt

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From: south jersey

97 expy 4.6 p0304 code

hi everyone
got the 0304 code yesterday...changed the plug...switched the#4 injector with # 1 cylinder and still got the same code.....getting spark from coil...anybody got ideas on what to do next before I take it to the shop? BTW it has been missing when I started it in the mornings but cleared up after 2 or 3 minutes and was fine for the rest of the day. did that for about a week or so. Also the truck has 258000 on it./ last time I changed the plugs and wires at 192000 all OEM

Vic

Apr 22, 2012 | 12:11 PM

Moto Mel

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From: Chesapeake, Va.

Quote:

Originally Posted by vics97xlt

This info is from OBD-II Trouble Codes - DTC Codes Car Repair

Causes

A code P0304 may mean that one or more of the following has happened:

Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer

You might want to check all of the above to possibly find the problem and cure it.

Apr 22, 2012 | 04:52 PM

alloro

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Quote:

Originally Posted by vics97xlt

got the 0304 code yesterday...changed the plug...switched the#4 injector with # 1 cylinder and still got the same code.....

How about the #1 COP, did you switch it with another one too?

Apr 23, 2012 | 12:08 AM

vics97xlt

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From: south jersey

dont have cop....coil packs

Apr 23, 2012 | 02:41 AM

alloro

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Quote:

Originally Posted by vics97xlt

don't have cop....coil packs

Okay then, same question, did you swap out the coil pack with the other side to see if there was any difference?

Apr 23, 2012 | 09:26 AM

vics97xlt

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From: south jersey

no i did not do that yet. but wouldnt more than 1 cylinder misfire if the coil pack was bad because it controls more than 1? today I am going to replace all plugs and wires just to eliminate the possibility of a bad wire or plug. then go from there.

Apr 23, 2012 | 09:44 AM

alloro

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Quote:

Originally Posted by vics97xlt

wouldn't more than 1 cylinder misfire if the coil pack was bad because it controls more than 1?

Most of the time the fine wire making up the coil breaks or shorts causing the failure. In such a case multiple cylinders will be affected. In other cases you might get damage to just one portion of the coil assembly, such as a cracked tower that will only affect one cylinder.

BTW, have you swapped out the spark plug wire to see if that's the problem?