Over the last couple of weeks I have noticed a slight stumble when I floor the throttle off idle and then the car has cutout a couple of times aswell.

Anyway today it stumbled and missed and coughed and spluttered and kept dying, it would not drive at all for a while. ( I thought I was going to have to have it towed home) I kept restarting the engine then it would die running lig a pig. Then finally it cleared and I drove 2 miles home as if nothing was wrong.

So I check my plug wires which were new last year when the opti was replaced 3,500 miles ago new msd blaster coil, new O2 sensors. No arking in the dark no burnt wires nothing anywhere near the headers.
I put new plugs in last week NGK TR6's ready for when I run my Nos for the first time.

I have an MSD 6AL ignition and I read a post once on here that they eat opti's. When it's missing and holding back it really feels like when the opti went before but can it go again so soon 3,500 mile?

I scanned the car with datamaster there were no DTC codes, if anyone could take a look at it, I would appriciate it cause it to complicated for me. It seems to only do this in closed loop.

I also have a freescan log of the car during the bad running the only thing that looked odd to me was my O2 sensors seemed to be reading really low when it was running bad down in the 200 range but when the car runs normally when I blip the throttle they are up in the 900's

 

I have disconnected my MSD 6AL to see if that helps and I am going to unplug the MAF and run on speed density to see if it runs ok on the PCM data for speed density.

 

So heres where I'm at I tried the car with MSD 6AL and MAF disconnected. I thinking if it happens only in closed loop then lets runs in speed density. it ran perfect for my 4 mile journey to work. So I reconnect my MSD 6AL and again it ran perfect.

My SES light and high speed fans were on all the time but no stumble or cutting out and the cars feels as strong as hell in speed density.

So this must mean my Opti is ok right?

So what other sensors are not used when you unplug the MAF, I know O2's are ignored but what else.

Or should I just get it tuned for speed density and forget about all those other sensors it runs so strong now with Mad Wolfs tuning.

COME ON YOU GUYS ARE YOU OUT THERE!