04 rx8 misfire help!!!

t72384 · 04-05-2014, 07:25 AM

Hey guys im kinda new here but im having high rpm misfires in my 04 rx8. ive read alot of information on the web but still cant figure this out. Ive replaced plugs, plug wires, coils, cleaned the ESS and mass air flow sensor. Its code P0301 front rotor misfire. please someone help

Dannobre · 04-05-2014, 10:40 AM

Have you pulled the plugs to see if they are all firing?

It isn't unheard of to have a coil or wire or plug that is defective out of the box. Use a coil tester to check the coils....

Have you reset the ESS profile? Sometimes you have to do it a couple of times to make sure it takes....

If all of that is OK...then you might want to do a compression check...if you have an apex seal problem that is allowing combustion gases to bypass the seal you can get missfires.....

Other than that...ECU, wiring, power and grounds to coils, wiring to ESS can all cause problems.

You will also have to check the fuel injectors...if one is not firing properly you could have a fuel related missfire

Good luck....

hoosier1104 · 09-04-2014, 09:01 PM

After you replaced everything, did you do the 20 brake presses to reset everything?

04-05-2014, 07:25 AM	#1
t72384 The Newbie Join Date: Mar 2014 iTrader: (0) Posts: 1 Rep Power: 0	04 rx8 misfire help!!! Hey guys im kinda new here but im having high rpm misfires in my 04 rx8. ive read alot of information on the web but still cant figure this out. Ive replaced plugs, plug wires, coils, cleaned the ESS and mass air flow sensor. Its code P0301 front rotor misfire. please someone help

09-04-2014, 09:01 PM	#3
hoosier1104 Dysfunctional Veteran Join Date: Oct 2013 Location: Plainfield, IN iTrader: (0) Posts: 4 Rep Power: 0	After you replaced everything, did you do the 20 brake presses to reset everything? __________________ Freedom is not free. Thank a veteran.

04-05-2014, 10:40 AM	#2
Dannobre Rotary Fan in Training Join Date: Oct 2008 iTrader: (0) Posts: 87 Rep Power: 17	Have you pulled the plugs to see if they are all firing? It isn't unheard of to have a coil or wire or plug that is defective out of the box. Use a coil tester to check the coils.... Have you reset the ESS profile? Sometimes you have to do it a couple of times to make sure it takes.... If all of that is OK...then you might want to do a compression check...if you have an apex seal problem that is allowing combustion gases to bypass the seal you can get missfires..... Other than that...ECU, wiring, power and grounds to coils, wiring to ESS can all cause problems. You will also have to check the fuel injectors...if one is not firing properly you could have a fuel related missfire Good luck....