obito

This month I've a weird problem. I got 04 Rx8, 138k mileages, just change spark plugs and coils yesterday. It is still be able to start fine, never go off during the trip. No misfire . Still can rev to 9k fine if it doesnt turn on limp mode ( when it turn into limp mode it gives me 40seconds from 0-50 ). At first, my car turn into limp mode then it threw up the code for bad CAT then I dropped my car at a shop. the mechanic said it was a bad CAT that turn on the limp mode, so I decided to take it off because new one will cost around 1400$. I picked my car up then few days later it is back again, so i gave it back to him then he spent a month and have no idea what happen because while he was testing it. It was running fine (btw I notice that he only drove for 7 miles). I can't wait anymore i took it back and go to another one who is an expert in Rotary. the new mechanic said it could be ignition coils then he took it out for me and show me and well it's burnt then he checked the code it just shows that CAT failure ,but it is normal because I took the CAT off. I was waiting for the parts for a week then my car going more horrible.
it is turn into limp mode no matter engine is hot or not. I've wait overnight, and it is still can't rev then I try again. I turn off the engine and restart it for few times when i still stuck on limp mode i will just turn it off then start it back again till it was not on limp mode, so I could drive ( i check by rev if I can't rev pass 3.5k rpm which mean still on limp mode. after that few day, i got my parts, and replaced them. 3 coils are burnt ,and most spark plugs are bad, so i thought it should be because of brunt coils. after that, my car turn back into limp mode again a day after replaced them. moreover, this time I can't cheat on them anymore no matter how many time I restart, but well sometime I could rev in N gear, but when i shift to first gear it will cut me to limp mode again. I 've do some research on the web they said it might be O2sensor or Metering oil pump, but It will give me codes for those possibility, but mine the car just show bad CAT code. My mechanic he said he would take it to the Dealer, but I know that it 's already run out of warranty because 130k already, but he said they just extended it again, and i try to google about that and i didnt see any extension anymore after Mazda extended 8yrs/100000miles warranty.

RX8Soldier

iTrader: (24)

what code is actually thrown? Limp mode is caused by a few issues.
At your mileage, I would say it is the metering oil pump and/or the lines. You said you removed the CAT? The CAT could be toast, but it wouldn't throw you into limp mode.
As for plugs and coils- How long were they on the car before you changed them?

dannobre

iTrader: (3)

Likely OMP if there is no code on an OBDII scanner

obito

code is P0420 Catalyst Efficiency low ......
coil and pluggs were on since last year. it was like 25-20k ago

dannobre

iTrader: (3)

The OMP doesn't throw a code often.....the CAT code isn't likley causing any problems with limp mode. I think that the ECT sensor and DBW throttle are the only limo mode causes, and they usually throw a code