Here is the deal, I changed my spark plugs yesterday because car was running bad and missing. Checked the wires and they were all fine. I put in a set of NGK TR6's and gapped them at .035 for nitrous. Here is what baffled me - all of the driver side plugs that I pulled looked fine, the passenger side plugs were all black like they were fouled out from running to rich. I put the new plugs in and car still ran bad - stuttering, popping , misfiring and running too rich (black smoke coming out bad when accelerating as well as strong gas smell). I checked the plugs again and same result! Any Ideas? Could this be the opti spark?

 

I have never heard of an opti making this rich/lean.Or even discriminating which side for that matter.I say you have a bad O2 sensor or an exhaust leak around that passenger O2. Somethings telling your comp. you're running lean on that side and the comp. is trying to compensate. Maybe a bad cat also.

 

Thanks for the info, I will check the o2 sensor.

 

The issues are happening as soon as the car is started?
Does it occur at WOT?

What is the condition of your plug wires? Are you positive that none of them have been cut by pulleys going along the passenger side up along the accessory bracket? Are you positive that none of the plug wires are burnt?

Start the car when it is dark out, and have the hood open. Make sure that none of the plug wires are arching where they shouldn't be. Sometimes it'll be a huge light show underneath the hood when its dark out. If that is happening, you probably need to track down a new set of higher quality plug wires.

Because it seems like it is a misfire only on the passenger side, I don't really think it is opti or O2 sensor related. However if you haven't replaced your O2 sensors recently, I'd suggest replacing them with AC Delcos. If you have Bosch O2s from a local DAP -- a lot of the time people have had issues with those O2s because they do not send readings quick enough to the PCM.

 

Even an exhaust leak in front of an O2 will throw off it's readings and is a vastly more likely cause than the opti.

 

Well , I have msd super conducters in good shape with heat sleaves on them. The problem starts a little when I start the car but gets much , much worse when warmed up.

 

I'm having similar problems, running rich, missing, and fouling plugs. I have taylor 8.2 wires with heat sleeves, new opti, new everything except the MAF and its still doing it. Tonight I'm going back out to take all of the plug wires off and inspect them and make sure they are run correctly and then install new plugs. I'll let you know what I find out

 

See that they open/closed loop from bad to worse sign. I call o2's.