2001-WS6

Well, I my head gasket on the passenger side went last week. The usual white vpor exhaust and condesation goup on ths valve cover. I was using a cup or two of coolant a day before I parked her.

I've got an MTI 422 in so I gave them a call to order the gaskets. I have the SLP LT's with custom ORP and O2 sims.

I spent two days going through JMX's site to do the install and everything went very smoothly. Nothing broke, everything reconnected without a hitch. New plus were put in as well. I did another walk through the connectors, coil packs and plug wires before getting ready to run the PCM relearn today. I setup a video camera to monitor the engine bay and had ATAP with all of the usual sensors up along with checks for miss fires.

She started right up and I let her idle for 5 minutes at 1200 rpms, then bumped it up to 1500 for 5 minutes before backing it down to 1000 for another 5 minutes. Oil pressure came up, coolant went to a nice 190, no fumes from the exhaust the whole time, valve train sounded normal and nothing more then the usual cold start noise that went away. The video camera on the engine bay catches a very slight exhaust leak on the passenger side header about the time I brought it back to 1000 rpms. I'll need to check that.

All going well so I'm going to let her idle on her own. She comes down to 900 holds, then a big back fire. She recovers, then holds and another big backfire. So I shut her down.

I checked ATAP twice during the relearn to make sure there where no codes being thrown that don't triger a SES. So, I go back through the ATAP logs to see what's going on. Well I had to shuffle my sensors around to get the miss fire ones in there and never realized that my Short Term Feul Trim B1 was running up to 52.2 at times and the Long Term Feul Trim was reporting up to 25 at times. Dohhhhhh! The B2's looked good. Still no miss fires reported and no knock retard either.

What the heck did I screw up? I'm going to pull the plugs now and see if there is anything funny going on there.

Rick

Pro Stock John

iTrader: (34)

I've had some backfire problems with my ARE 422ci here and there, and they were from having a damaged/pulled/melted Crank Position Sensor wire, which runs down the firewall by the #4 and $6 header primaries.

Backfire to me = unburned fuel hit hot exhaust pipes...

I'd scan for sure... Is the car running on all cylinders?

2001-WS6

When Detroit Speedworks put in the MTI 422, we super shield the wiring because the SLP LT headers were all ready cooking some it with just the heads and cam.

I did just turn the ignition to on to hook up ATAP again to check one more time for codes. Low and behold, there was a P0135 in there which is one of the O2 Sensor Heater Circuit errors I believe. I'm assuming driver side base on the funky readings there. I would have thought that should have popped up sooner at the 5 minute and 10 minute checks I did for codes.

I've started some research on the code and it looks to be a common one that is being tossed by SLP LT headers with ORP and rear sims. We just did the ORP install with the 422 so I'm guessing that it may just turn out to be a bad O2 sensor on the driver side.

So I'm thinking the funky O2 readings are calling for more fuel which when the RPMs dropped to below 1200 wasn't getting burned off. Excess hits the headers like John says and pop. I still need to check the plugs on the driver side but I'm feeling a bit less scared now. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

What's everyone think?

Rick

2001-WS6

Well, I replaced the suspect O2 sensor on the driver side. It looked pretty well cooked but the problem is the same. The wiring is shielded from the header so there is nothing exposed there. There's no more header leak and that was actually the passenger side anyway. So there really must be some unmetered air getting in there after all.

So I guess it's time to pull the intake manifold and reseat the injectors again to see what happens. It just seems odd to me that it would only be one side if it were the intake and I'm not sure how the injectors could be letting air by their seals. <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

Rick

y2khawk

iTrader: (5)

an exhaust leak before the O2 sensor will cause the fuel trims to go way up. You'd be surprised how little extra fresh air in the exhaust can throw things off.

just a thought