KA24de wont rev past 4000 rpms!?

[AbandonedTeddy]

So yeah my s13 wont rev past 4000 rpms i dont know why it started today been fine the past 5 months. All i tried today was unplugging maf and running it like that but it still didnt go past 4k. Everything seem plugged in. New to these cars and dont know much about pls help thanks. Advanced timed at like 18 degrees idles around 1800. Backfires a good bit also but I think that because of EGR delete I did it runs rich. No 02 sensor either. It just backfires and is clunky when I try to rev over 4k.

[centralcoaster33]

Hi There and welcome to the forums! My first thought was that your transmission position switch could be stuck for 5th gear triggering the computer's speed limiter. But, it seems you've also been 'modifying' a few things. No exhaust sensor can possibly create poor operating conditions and the engine is in limp mode. EGR delete could be an issue if done incorrectly. I'm not sure about those, but you have had a running car up until now, so we'll just make a mental note. I think you should check your ECU for codes. That will tell you where to look next. Go ahead and plug your MAF back in (good idea looking at this by the way). This link tell you how to do it and if you possibly have an older s13, there's another link in there to get to that write up as well.
1991-1994-240sx-reading-computer-ecu-codes-t253912.html Let us know what you find. Thanks.

[PapaSmurf2k3]

Yeah unplugging the MAF will make it go to limp mode, but you should have codes in the ECU telling you what is up as well.

Is there any reason why you're not running an O2 sensor?