Theflyingkivi

I have a 04 rx8 231 hp with almost 100 000 km on it. It has a spots intake. Apart from that, stock engine whise.

As I took it out of its winter sleep I noticed that it's way down on power and it won't rev all the way to redline. But end of last season it was running great.

I have no check engine light or any fault codes, I have checked with a professional Delfi reader.

The cat was changed less than a year ago due to failed emissions test.
I have changed the ignition coils and leads (one coil was broken so it got a little bit better but it's still far from good).
The sparkplugs was changed less than a year ago, I have tried changing back to the old plugs and it makes no difference.
I have cleaned the MAF sensor, and wiped of the ess.

What more can I try, I am running out of ideas.

Loki

iTrader: (1)

Did you give it fresh gas? Last winters is bad by now.
To diagnose further you'll need to hook up an OBD reader and look at fuel trim data ( give it a couple of drive cycles to learn the trims). If they're not near 0, it will give clues as to what might be happening.
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Theflyingkivi

I have given it fresh gas.
If I remember correctly from when I had the obd reader connected there were 2 fuel trims, I think one of them was off by quiet a bit. I have to check again. Wat does it mean if it is off?

Loki

iTrader: (1)

So on a warm idle, if the long term fuel trim is over about +7 you have a vacuum leak. If you see negative fuel trims that's very often a problem with the intake (many after market intakes cause more problems than benefit). Share what you find.

Note the car has to have had time to learn the trims, so a few drive cycles. Share what you find. Ideally, rpm, airflow g/sec, short term and longterm trim, and afr altogether on a warmed up idle.

BigCajun

iTrader: (1)

Did you reset the NVRAM?

(20 brake pedal stomp?)