Austin22

I am currently having a problem with my 04 rx8 98,682 miles a.t. trans, mods include top speed catless midpipe and stock air box k &n air filter. The problem I am running into is having trouble getting to redline. Under moderate load it will reach red line just fine, but under high load I can only achieve redline in first gear. In the past 6,000 miles iv changed the fuel pump airfilter checked for air screens, cleaned ess sensor and installed catless midpipe, and spark plugs wires and coil paks have been changed the problem isnt as severe as it was after all the repairs, but it still exist. Any tips?

Colon Terminus

Define "moderate load" and "high load", please.


I'd suggest you clean the MAF, IAT and whilst you're in there clean the throttle body and check that there's nothing in the intake pathway obstructing/disrupting airflow. You are running premium gas, right?

Austin22

Moderate load, or half throttle easing through the rpms and high load, or full throttle. The car pulls strong up until about 6,400 rpms in 2nd gear and up after that point I can feel power loss n the car will kinda idle itself out..I forgot to mention that I have cleaned the maf and throttle body along with the air intake accordian while all other things were done. Iv always ran 93 premium gas which is the highest we have around, with alittle premix with amsoil.

Colon Terminus

Sounds like you have done/are doing all the right things. also sounds as if the ECU is sensing impending knock and throttling you back.


Have you tried inspecting/cleaning the SSV? There's a DIY around here somewhere.

Austin22

Other than operating the ssv valve with a hand pump to see if it moves freely I haven't tried to clean it. I will look up a dyi on it amd see how everything goes from there. Thanks for the help and advice.

Austin22

Got around to cleaning the ssv valve yesterday, about a six hour job for me. After replacing the coolant and changed the thermostat while I was in ther the car seems to be running a tad cooler than before. The valve and housing wasnt as bad as I was expecting. After a 30 min drive I noticed slightly more power at the 5500 rpm mark, but shes still having the trouble getting to redline in gears 2nd and up.

Colon Terminus

After you did all the above work on it, did you reset the ECU?

Austin22

I reconnected the battery after work was done also along with the 20 brake stomp. I only drove for about 30 mins, you think I should do some more trips to give it tome to relearn the fuel trims?

Colon Terminus

I would. Couldn't hurt.