Running rich?

[Davidw04]

I have an 04 Mach with 55k miles. I had to return the car back to stock tune for emissions testing reasons and when I get off the gas in higher roms I get the crackle in the exhaust and when I start the car or let it idle for an extended period of time the car starts smoking. It's a white/ grayish smoke that burns your eyes. It is not coolant or oil. Please help how can I fix this? I have an intake, flownaster weldins, upr off-road x-pipe with mil eliminators. Car seemed to never smoke before tune I also recently checked and re gapped my plugs to .052

[TKat13]

Originally Posted by Davidw04

I have an 04 Mach with 55k miles. I had to return the car back to stock tune for emissions testing reasons and when I get off the gas in higher roms I get the crackle in the exhaust and when I start the car or let it idle for an extended period of time the car starts smoking. It's a white/ grayish smoke that burns your eyes. It is not coolant or oil. Please help how can I fix this? I have an intake, flownaster weldins, upr off-road x-pipe with mil eliminators. Car seemed to never smoke before tune I also recently checked and re gapped my plugs to .052

If you put the stock tune back in to pass emissions, then I would think you would also need to get rid of the mil-eliminators and install your cats.

[Davidw04]

I have gotten my cars through without cats. They don't do a visual inspection they look for check engine lights and that all the sensors are reading

[TKat13]

Understand, but your question was about running rich; if you have mil-eliminators in there with a stock tune, the O2s are not telling the computer the proper info for the computer to add or subtract the fuel. Unless you are only running them on the rears.

BTW, you really do not need the mil eliminators on the rears, the tune can just turn them off.

You mention intake; do you mean you returned back to the stock intake or are you also running an aftermarket there as well?

Is your fuel pump stock?

[Davidw04]

I only have the mils on the rear o2 sensors. Stock fuel pump and a jlt ram air intake

[Khyren]

Semi on topic and semi thread stealing... When I change the tune on my Mach in any way, I let the computer get through all of it's checks and don't get on it hard at all until they are all done. After it is done, I will do a few WOT pulls in 4th to help it tune the WOT maps. Inevitably though, the first time that I do a 1st and 2nd gear WOT pull, it will smoke like it is pig rich until the end of 2nd. Shift into 3rd and it's all gone. The car runs beautifully and still gets 23-25mpg hwy but that running rich thing baffles me. It has only started this since the catted X-Pipe install. I left the downstream 02's in their normal locations so they are technically reading opposite air streams. To my knowledge, they only are there for catalyst function and nothing to do with air/fuel ratio.

[01yellerCobra]

At WOT the ECU isn't using any of the O2's. They're only used at part throttle and idle. As for the rears you are correct aboit them only being used to make sure the cats are working. Chances are it's always run like that and you only see it now because there aren't any cats in there. Who tuned it?

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[Khyren]

No one in particular tuned it. I have been running the default SCT Mach 1 tune for about a year. With the factory H-Pipe, there was never any super rich smoke. Possibly because there was 4 cats. Now with the X-Pipe, there are only 2 high flow ones.