#2 Misfire

Hi All,

I have 1999 Venture and am getting a misfire on #2 cylinder, it showed a code PO302 on a friend's code scanner. I pulled the spark plug out yesterday and it looked good to me, except for the gap which was over 1/8". It wasn't wet looking and a good color in my estimation. I went ahead and regapped it and put it back in for now.I figured where the plugs have nearly 100,000 miles on them, they are probably on the way out anyway.
What seems strange to me is, it only seems to bother when the engine is cold. After it warms up it runs fine, or it appears to. I know the mileage is off a little, but I attribute part of that to the new ethanol gas we are forced to use now.
I guess my next move is to try swapping a couple of plug wires to see what that will net me. If that's all it is, great.
The friend with the scanner says he had the same problem on a GMC pickup and it ended up being a bad fuel injector. Is that a very hard job? He claims it was pretty tough to do. Of course he is just a weekend warrior when it comes to auto mechanics.
I should mention that this engine has a lot of miles, 183,000 or so and I am hoping the lower intake manifold isn't going again as I've had it done once before by a dealer at around 83,000 miles and it was costly. I don't appear to have any coolant loss to speak of and no signs of any oil in the expansion tank. ALthough the low coolant light does come on occasionally, but I attribute that to a dirty sensor as I know its full.
If its a major repair, with the mileage, I will consider putting this one out to pasture, because it may not be worth the money at this point, with the rust that's creeping into it.

Thanks for you input on this one guys. Toni.

Toni,
Having the same problem with my '97 (182k) when cold. Feels like running on 4-5 cylinders for about the first half-mile or until warmed up. Throws two codes which I will report back on tonight when my wife has the van back. Had them read a while back, but have not fixed the problem. Will definitely do before my smog is due this Oct. Have you had even one of the O2 sensors replaced yet. My mechanic replaced the first one in the line about a year ago.

Night update: Mine was a P0300 code: Random/Multiple Cylinder Misfire. P0140: Low 02S Activity Bank 1 Sensor 2. P0141: Heater Circuit Bank 1 Sensor 2. Basically my mechanic w/o looking at it is saying it could be a numebr of things in my case. The 2nd 02 sensor in line he said would be first to try.

With your latest update, have you tried to put your hand a few inches away from the tailpipe and it should not get burned by the exhaust. It s/b slightly warm. If it is getting burned with steamy smoke, it's your head gasket again. Stay away from the "stealership" on this one and go to a reputable mechanic. When my temp gauge was fluctuating widly it was first the LIM and then it went to the blown head gasket a few miles later. Mine would only run about a mile before it would overheat.

At 183k like my '97 has as well, I will not be fixing any more major repairs to this Venture, but take my $800 or so and run. Let the next guy or auto shop at a local school have the next learning experience. The Honda or Toyota minivan will be next. Keep us poste though if you do end up fixing it with what it turned out to be.

Yes, I changed the Bank #2 oxygen sensor last Summer. It did help with the running of the engine, but I don't think its related in this case.

When I went with it this morning, the temperature went crazy. At first I thought it was the thermostat, now I have a feeling its the head or lower intake manifold gasket. Time will tell I guess....