I was out messing around in my car today. And it seems like my car cuts out above 4500-5000+ RPMs. It feels like the car is hitting a rev-limiter, but the car doesn't have a rev-limiter. There is a SES light, but that's because my MAF has took the boot, I just checked the codes, just to make sure that it was still showing just the MAF as a trouble code. All my wires seem to be in pretty good shape, and this only happens in the upper RPMs. Could this be a opti, bad plug(s)? Any help would be great.

Mods are listed here.

 

Could be valve springs.

 

I was talking to a friend of mine, and he said it could be a bad coil. Does this sound like a bad coil? Thanks

 

It is possible, yes.

 

Best to repair the MAF first. Don't know who did your computer tune but perhaps there is a problem with the speed density map and since you have a MAF problem, it may be related. Fix what you know first and then speculate after that.

 

could it be a clogged cat?

 

Another Vote here for clogged cats...

 

I couldn't be cats as I don't have any. And I doubt it's the MAF, because I had this tune for about a year before it decided to act up like this. I'm pretty sure it's the coil. I'm putting heads on my car in a month, so I hope to get everything worked out by then.