What are the results of code PO300.

Tiny
CE2BUBBA
  • MEMBER
  • 2002 SATURN L200
  • 141,000 MILES
I have a 2002 Saturn L200 2.2 Liter ecotech, it is giving me the code PO300 random/multiple missfire. I have changed the coil pack, spark plugs, ICM, and the crank shaft sensor. I have 148 psi on fuel pressure. The compression reads from left to right 150, 150, 160, 142. The car idels fine in park and in drive. When in drive and gas is given it shudders real bad and has no power. Please share if you have any other suggestions. Thanks!
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Thursday, September 1st, 2011 AT 1:31 AM

14 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
If the fuel pressure is that high, the regulator is bad. It should be between 50 and 60psi KOEO.
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Thursday, September 1st, 2011 AT 1:38 AM
Tiny
CE2BUBBA
  • MEMBER
I'm sorry, fuel pressure was at 48 psi not 148 psi.
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Thursday, September 1st, 2011 AT 2:55 AM
Tiny
SATURNTECH9
  • EXPERT
Just to add to this one have you checked the exhaust back pressure?I have seen a lot of plugged cats on thpse cars.
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Thursday, September 1st, 2011 AT 3:14 AM
Tiny
CE2BUBBA
  • MEMBER
I crawled under the car and banged around on the cats, I was told that that they would sound solid if the were plugged. They did not sound solid at all?
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Thursday, September 1st, 2011 AT 3:18 AM
Tiny
JACOBANDNICKOLAS
  • EXPERT
That sounds better. Next, do what saturntsch9 said. He is correct with the catalytic converters being plugged. If it is, it may get hot enough to glow red. That will help you know. You may need to check back pressure with it.
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Thursday, September 1st, 2011 AT 3:19 AM
Tiny
SATURNTECH9
  • EXPERT
The best way is to screw in a exhaust back pressure gauge in both exhaust manifolds one at a time where the o2 sensor goes I would never use the glowing red or the bang method.I never say those tests in the saturn service manuals lol.
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Thursday, September 1st, 2011 AT 3:30 AM
Tiny
CE2BUBBA
  • MEMBER
I will check that out. Thanks. Just FYI, I drove the car home from work last Monday and it ran fine. The next morning I got in it to leave to go to work and as soon as I put it in drive and took off it started to shutter real bad and had no power. I just parked it and drove my gas guzzling truck and have been since. Do the catcons go bad like that? Just one day they seem to work fine and the next a bucket of crap?
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Thursday, September 1st, 2011 AT 3:49 AM
Tiny
SATURNTECH9
  • EXPERT
Iam sorry I miss read I thought you had the L300 with the V6 3.0L So to do a back test you would just screw the tester adapter into the one exhaust manifold where the o2 sensor goes. Those engine also get a lot of plugged cats. It sounds like you could have a timing chain that jumped those 2.2L had a problem with jumping and breaking timing chains.I have heard of them jumping time just starting them up.
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Thursday, September 1st, 2011 AT 7:20 AM
Tiny
CE2BUBBA
  • MEMBER
How would I know that it jumped time? I have also heard and read a lot about these cars breaking the timing chain, but most everyone says that it was at highway speeds. I know that the car will not work at all if the chain breaks. I have not heard much about jumping time?
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Thursday, September 1st, 2011 AT 11:12 AM
Tiny
SATURNTECH9
  • EXPERT
The first one I saw had just got a oil change at a lube place and would run rough at idle and set a P0300 as soon as you gave it some gas it would run good.I went over the basic stuff then I worked with the engineer that designed the engine on the phone I tested everything he asked me to and everything checked out. Then the last thing he tells me is these engines have a problem with the timing chain tenisors and chains and that it could have jumped time. But he said the only way to make sure the timing marks are on or not is turn the engine around and around up to like 37 revolutions until the colored timing chain links show and are or are not lined up with the cams timing marks on the sprockects and the crank pulley marks are lined up. Come to find out all the marks were lined up except the intake cam marks were off by two teeth.I put a new timing chain kit in it and it ran great. You will have to remove the valve cover coil cassatte spark plugs etc before you start looking for marks. Let me know if you need the timing mark set up.
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Thursday, September 1st, 2011 AT 3:51 PM
Tiny
CE2BUBBA
  • MEMBER
Will do, thank you very much for the help. I will respond as soon as possible.
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Friday, September 2nd, 2011 AT 1:09 AM
Tiny
SATURNTECH9
  • EXPERT
Your welcome keep me posted.
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Friday, September 2nd, 2011 AT 3:10 AM
Tiny
CE2BUBBA
  • MEMBER
Wanted to up date you with the repairs on my 2002 Saturn L200. The ICM and the Coil Pack were bad. Got both from Auto Zone. I would not recommend buying any parts there. Thank you for all your time and effort.
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Tuesday, September 6th, 2011 AT 6:59 PM
Tiny
SATURNTECH9
  • EXPERT
Your welcome thats what were here for. Glad to hear you got it fixed sorry to hear it turned out to be bad new parts.
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Tuesday, September 6th, 2011 AT 7:11 PM

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