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Discussion Starter #1
Hello I have a 2000 Passat v6 and I got a CEL and the codes are:
P0300
P0306
P1423
P0304
P0302
I know the codes with 300 on it Are misfires but not sure about the other one also I think I read some where that when misfire codes are across from each other like 2 & 4 that means the coil is bad can someone confirm that

thanks in advance
 

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Start with checking the SAIP system. It uses vacuum to activate the combi valves. The hoses break and you end up with a vacuum leak that can cause misfires. By now, all of the vacuum hoses should be replaced (unless already done). Also check the plug wires, if original, try misting them with a spray bottle at night and look for arcing.
Then onto the plugs. How old, what brand and is there oil in the plug well?
There should be a few SAIP diagnosing threads on here, some with pics.
 

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Discussion Starter #3
Start with checking the SAIP system. It uses vacuum to activate the combi valves. The hoses break and you end up with a vacuum leak that can cause misfires. By now, all of the vacuum hoses should be replaced (unless already done). Also check the plug wires, if original, try misting them with a spray bottle at night and look for arcing.
Then onto the plugs. How old, what brand and is there oil in the plug well?
There should be a few SAIP diagnosing threads on here, some with pics.

I only had the car a Couple of months. I have pulled the wires and there's no oil on the wires haven't pulled a plug yet cant find my plug socket picking one up today. I will look up one how to Check the SAIP thanks for the info will report back soon.
 

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Discussion Starter #5
So here is a update i check all the hoses for the SIAP and the look good. Then i found out my brother was being cheap and put 87 gas in the car so i drive it all out and filled up then i got VCDS Lite and cleared all the codes. drove for about 100 miles and check engine light came back on and this is what i got this time
P0300, P0304, P0306, P0102, & P0442
 

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87 octane is not a problem. You have an evap leak, a low MAF reading and misfires. Fix the evap leak then see if the other codes come back. If so, move onto the MAF reading and see what it shows. It could be an intake leak after the MAF, either the flex tube to the throttle body or the seals at either end of the plastic throttle body inlet.
 

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Your misfires are on both banks. I would start with the plug wires, since they tend to bake to a crackly crunch over time, while the coil seldom goes bad.
 

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Your misfires are on both banks
They were on both, but 4 & 6 are on the same side.
I had some misfires in 2 all the time when I adopted my 02. VCGs, plugs, wires all replaced. still had misfires in 2 when it was wet.
New coil pack, misfires are gone. I tried the old wires, no misfires there either.
This is on an '02 4Mo GLX Wagon A/T with the 2.8L ATQ
 

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Discussion Starter #9
Hi guys,

been busy sorry for the late response. I put a new coil pack in the car still has the misfire on #6 so i'm waiting on new wires to come in and i will change them and the plugs. the other codes haven't come back yet so I don't know whats up with that will report back with update as soon as I get the new parts in.

once again thanks for all the help
 

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Hi guys,

been busy sorry for the late response. I put a new coil pack in the car still has the misfire on #6 so i'm waiting on new wires to come in and i will change them and the plugs. the other codes haven't come back yet so I don't know whats up with that will report back with update as soon as I get the new parts in.

once again thanks for all the help
swap your passenger and drivers side wires (at coil pack too) and then if it moves you know its the wire....
 

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I would check the compression since the plugs, wires, injector and coil should be good.
 

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Discussion Starter #17
After i got home from work i scanned the car again and #4 is back for a misfire. I was wondering if a weak fuel pump can cause this. I say that because if I let the car sit for a day or more its hard to start at 1st I thought maybe the battery was going but its not that had the checked. While reading at work instead of working i saw something that said there's a chance a weak fuel pump or clogged fuel filter can cause a misfire what are y'all thoughts
 

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I'm getting into this late in the game.
So this last time you scanned for codes, the only code is a P0304?
Are all of the other previous suggestions, issues taken care of?
A fuel filter is only $10 ~ $15. It probably has never been changed, doing so certainly won't hurt anything.
 

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A fuel pump, or weak/clogged filter will not cause a single cylinder miss. That'll tend to more of a multiple and random misfire. The computer is setting a significant drop in engine speed on that one cylinder, which is why it is singled out. Find out what's wrong in that hole.
 

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i was hoping you didn't say that
It's the standard checklist for any starting problem. An engine needs spark, fuel and compression. You can borrow a compression tester and most parts stores with a deposit.
 
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