I know I thought I had this problem solve before... BUT today I finally got the bottom of my CEL/Wrench light problem!!!! Let me backup a bit... I though I had fixed my problem a couple of weeks ago... car had been running great... no sign of a wrench light or CEL... I was positive I had it. Well, last week the dreaded wrench returned!!! This time is was much more stuburn!!! I was happening a lot!!! ARGH!!! I was becoming one cranky guy! With a bit of pleading I got Zex to send me a new Nitrous Management Unit... I mean we had checked everything.... and it only happend when the Zex was connected (even though it was off!) So Zen graciously agreed to send me a replacement unit... It showed up today. I swapped out the unit... I no more than got half way around the block and bang, WRENCH LIGHT AND CEL!!! ARRRRRRRGGGGGGHHHHH!!!! So back to the drive... go over EVERYTHING again.. I just redid every connection.. I am totally baffled... Ok... so it has to be something with the Throttle Postion Sensor... There is that one TSB the matches up with what I'm seeing... So with TSB in hand I go to my Ford dealer... Service guy says, disconnect the Zex wire from the TPS so it looks like stock and they can do the TSB... ok.. fair enough... It was closing time so he took all the info and said he would call tomorrow... So I head home... I get home and I think... Ok... I've checked everything.... Then just for grins i decide to check one more thing.... I pull the connector off the TPS... Wires look good, they are nice in solid in the connector... The wires go into a female connector.. On the TPS itself of 4 blades to slide into the wire connector.. Looks ok...Then I put my nose way down there.. The way the blades are in the TPS makes them hard to see... So I really get down there... and I squint to see the top blade which is the one that is the important one... WAIT A MINUTE!!! The top blade is like a 1/4 of an inch SHORTER than the other 3!!! I mean it was all i could do to see it! So I grab a pair of needle nose pliers and I ever so gently pull the blade out... At first it didn't want to move... but then it moved ever so slightly! HMMMMMMMM... So I carefully put the connector back on..... And it's off for a test drive!!!! VVVVVVVRRRRROOOOOMMMMMM!!! NO WRENCH LIGHT!!!!! WOOHOO!!!! I am positive I have finally found the culprit!!! This time iis actually makes sense! I hope I'm not jinxing myself here but that has to be the problem... the wrench light was coming on everytimg I really stepped on the gas this afternoon... after I made the fix... nothing and I went out on the back roads and went WOT a number of times!!! Soooooo... hopefully this info will save anyone the agony i went through if they get the DREADED WRENCH LIGHT!!! I'll be call Zex tomorrow to thank them again and apologize... LOL!