Sputtering-Now dead

I need some help as I am abou to do some major trouble shooting. A few weeks ago my car started sputtering once I changed out my catless downpipe and put on the stock for inspection. The next two weeks were terrible. At first it would sputter once it warmed up, usually 10 -15 min. Then it started doing it after about 5. After the inspection I removed the stock and put the catless downpipe back on that Satuerday. It continued to putter all week until Thursday mouring. When it started doing it this time I was in a straight away so I gave it a little bit more gas. I t started to pick up but then I heard a pop like a backfire then there was no engine response. I push the gas and no noticeable engine rev, just tach reved up. Since then I have pulled the plugs and cleaned. Was unsure of were the coil packs were. I have also disconected the ECU(APEXI FC) as I have no AFM. After putting everything back together it still did not start, sounded like battery. Pulled battery out of wifes car still nothing, maybe starter. I welcome all sugestions. Need to get it running as the weather is changing.

Well I guess there is no one who can help me out. Well after reading many other forums I have begun my own study and trying out various test. Thanks for nothing. Hopefully someone will put in there two cents soon.

I need some help as I am abou to do some major trouble shooting. A few weeks ago my car started sputtering once I changed out my catless downpipe and put on the stock for inspection. The next two weeks were terrible. At first it would sputter once it warmed up, usually 10 -15 min. Then it started doing it after about 5. After the inspection I removed the stock and put the catless downpipe back on that Satuerday. It continued to putter all week until Thursday mouring. When it started doing it this time I was in a straight away so I gave it a little bit more gas. I t started to pick up but then I heard a pop like a backfire then there was no engine response. I push the gas and no noticeable engine rev, just tach reved up. Since then I have pulled the plugs and cleaned. Was unsure of were the coil packs were. I have also disconected the ECU(APEXI FC) as I have no AFM. After putting everything back together it still did not start, sounded like battery. Pulled battery out of wifes car still nothing, maybe starter. I welcome all sugestions. Need to get it running as the weather is changing.

It would be easyer to help you if you said the year maek model of the car.. and weather or not it was a 4 or a 6 cyl

It is 92 Skyline GTR

Well I finally got my R up and runnign again about a month ago. Turns out it was the power transitor. Cost me about $80 and got a second one some time later for future.

What the heck is a power transitor? Got pics?

have been having the same issue with my GTR r32 and its super hard to get any help here in the states especially in california
will try it myself thank you