Can't hit redline
 

I have an S5 GXL and starting on wednesday, I can't hit the redline of 8k. I could do it just fine on Tuesday and now it gets to 7k and just stops, i can put the pedal to the floor and it won't budge from 7k. I usually run at least one good run every day, where I redlione first, second and third. I heard it's good for rotaries but now this happened. Any help?

have you checked to see if there are any engine codes

how do u chek for engine codes?

My check engine light comes on for a couple of seconds sometimes and then it turns off. I bought a new O2 sensor and I'm putting it in today.

well if it is coming on at all, you probably have error codes which can put the engine in limp mode or reduce output.

And randomly replacing parts without know what the issue is, can be very expensive.

how do I pull the codes?

I've heard of red lining your engine to be good, but every day from 1st to 3rd, thats a pretty serious load on the engine to do every day. Try just doing a 2nd gear pull or 3rd gear even.

If you cant reach 8k, could be your ignition, spark plugs, a bunch of various things. Since I personally have never encountered this problem I cant be very helpful, but check things that are an easy fix first like your spark plugs.

i had that problem once . it was my spark plug wires . check your ignition system as spoolage said .