I recently bought a good cond. 99 SE LE manual trans. It runs good and Idles good but
if I take it up to 5500 + rpm's it cuts out and jerks. If I back off it starts running smooth again. Last night I was at 6k rpms in 3rd and the CEL blinked 6 times and went off. Anyone ever hear of this? I'm guessing it could be coils-spark plugs. I haven't checked for Hanshins yet.

 

Check for codes, blinking CEL usually means misfire or multiple misfire. You can use a cheap obd II scanner.
Check out the Stickies for CEL codes.
https://maxima.org/forums/4th-generation-maxima-1995-1999/76800-check-engine-light-diagnosis-if-trouble-lights-read-here-first.html

 

Ahh, the 99 misfire once again. Coils, you can try to clean the section where the spring meets the coil in the stalk, or just replace them. The misfires usually show up under a load because the spark isn't strong enough.

 

Since I switched to 93 octane it hasn't cut out 1 time......better power and not cutting out or flashing CEL... I got a decent deal on a used replacement set it case I need replacements.

 

Gas is at crazy low prices. Splurge for the recommended 93 octane

Sounds like your coilpacks are on their way out (99's are famous for coilpack issues). But of course, check and replace spark plugs first.

Order to check/replace.
1. Spark plugs
2. Coil packs
3. Injectors