O2 sensors should be throwing a MIL if that's the problem ...

 

I would think so too, but I'm gonna ask brenspeed if they shut the codes off with the tunes they do. I would want them on and tuned so that it doesnt throw codes, but i seem to remember a conversation with somone from there and them saying something about just shuting them off, anyway though, looking at plugs and CoPs now.

 

If the O2 sensor is tuned out then I would think that it wouldn't be able to send anything back to the PCM that would affect the operation of the engine. It's my understanding that this is why they are generally tuned out, because if they weren't the parameters they return would cause undesired operation and a MIL.

 

Yeah but that's the rear 02's they can throws codes all day and not effect engine performance since there only there for emissions. The upper 02's well effect engine performance since those are used to calculate A/F mix.

I also am having a problem kind of like yours, intermittent missing for no reasons, and it's very obvious, I had to take it in to the one dealer there that has a high performance division, they do dyno tunes and etc. Just took it in today, see what they say, I too was also thinking a COP or maybe a bad injector?

 

You need to have someone with experience tuning our cars look at a data log. Ford service techs/mechanics are clueless when it comes to the different parameters for the aftermarket supercharged Mustangs. If they did hook up the disgnostic tool it would tell them everything is all out of whack and they would start telling you your O2 sensors are bad, your MAF count is off blah blah blah.

I went through the same things you are. Find a tuner, send a data log. Problem solved.

I would put the stock TB back too.

good luck.

 

Thanks for the info simon. I am going to continue tying to fix the issue myself, but after my next two attempts at fixing this, that will be when I consider brining it somewhere to get fixed.

 

I have to agree with Simon and he stated it in more then one thread....throw some of the cash your using to replace everything at a trusted S197 tuner and see what he comes up with....they can see fuel trims, A/F ratio, if the fuel pump is operating properly (voltage etc), and so many other things and do this in real world times and actually diagnose the problem. I should have read this thread first before my long winded post in your other thread....thanks for the props too in the other thread....you could tell where I was heading and I wanted to be subscribed to see if it remained heated in that thread....I understand anyone can get frustrated and it was nice to see you own up and apologize for a few of your remarks....I have seen many another thread go south and much worse then you and others had stated....so after the COP's and plugs if that is not fixed go to a tuner!!!!!! let us know what happens

 

Will DO! I know if I dont get it with the next round of stuff, I am beyond simply being a sensor and have either a bad tune or damaged a more serious part that needs to be replaced. Either one will get much more expensive quickly.


Quick question to anyone here, are the front and rear O2 sensors the same? I know they do not perform the same job but wondering if I can swap front with rear to see if I have a problem with one or the other.

 

Stop throwing parts at it! You have the interceptor gauges, so what do the fuel trims look like? How about your O2 signals? You can record different parameters with the gauges and then play them back, so try recording anything that could cause a problem like fuel pressure, timing, etc.

 

been monitoring the fuel pressure on them, I actualy liked my Predator better then this SCT cause I was able to do much better data logging with it. The software they give you for free was sweet, I could record in real time and have like 15 gauges or more going at once.

Actually.... that gives me a idea. Anyone know if I can datalogwith a predator without it being married to my car? I know I can not flash or modify tune with it, but if I am thinking right, i probably can data log.