Need help please: sluggish power at wot til 6500rpm
 

I have a 04 rx8 6spd with 80'XXX miles, I have a BHR midpipe (no cat), BHR ignition coil kit just installed 2 days ago, yellow optima, deleted air pump, custom single side exhaust, stock intake without VFAD.....

Codes showing: ( I am searching right now)

P0300-Random misfire

P0410-Secondary air injection circuit fail

P2259-AIRsolenoid valve control circuit high ON 2 CCM"

P0138-Rear O2 Sensor Voltage High

P0037-o2 Sensor Heater voltage low

My problem started after I let the car sit for week due to me going to houston texas while my home town was sitting at 30° all week. I came back home, got in the 8 and turned her on without any problems after letting her warm up I took her for a drive. But quickly noticed that my lower rpm power is sluggish til about 6500rpms then the power kicked in. I did every step on the "Misfire Topic" with no luck so I took my car to Mazda for a compression just to make sure my engine isn't giving, the results:

No1 (677.69/709.69/693.69)
No2 (687.69/660.69/682.69)

My next step tomorrow is the connections behind Intake manifold and checking for vacuum leaks.

I'm moving to Houston next week so any help before I go would be highly appreciated. .....Thanks!

What's the RPM on that test? If those are normalized to 250rpm, your engine is only barely not failing, since failing at 250rpm is about 656-660kpa.

But, it wouldn't produce a 'power kicked in' result.



P0410, P2259, and P0138 don't matter here, all emissions related, won't affect power.

P0300 is probably firing as a result of whatever is causing your problem.

P0037 needs to get fixed. That COULD be the problem, if the ECU is crippling the car because it doesn't know what your actual AFRs are, so it is spewing fuel in to keep it from a chance of being too lean. That's a critical sensor anyway, and you need to get that resolved. That code is usually a sensor failure, but could be a wiring problem.

When you get the sensor replaced or the harness repaired. CLEAR YOUR FUEL TRIMS before you go driving. Then let the car idle warm, and idle for another 5-10 minutes. Then see how it feels.

On my paper it says speed of rev: 199
If it's barely passing then I guess having my engine rebuilt will happen this summer......

As for that P0037 I'll get on that asap...Thanks!

199rpm? your engine is doing pretty good then, normalizes up to 7.9s and 8s. A good engine. (see this chart in the new owner's thread: https://www.rx8club.com/new-member-f...4/)

However, 199rpm means your starter is nearly dead. Fortunately, a new starter is a lot cheaper than a new engine

I'm currently looking into the 2k starter I believe my starter is the original since day one.....

So I went ahead and bought the 02 from mazda and my starter should be here sometime today, which is good cause after I got my ride back from mazda my 8 starting taking forever to turn on......smh
https://cimg0.ibsrv.net/gimg/www.rx8...104c3bb982.jpg


Out with the old in with the new....

I think mazda tried setting me up for failure, I was taking off my starter when I noticed that both bottom plugs where unplug and hanging there.......smh

Ok so i've been busy trying to get this problem solved before i move. After doing all things i read about i went back and got my codes checked i got:

P0300
P0410
P2259

The things ive done so far (not in the order listed)

BHR Ignition coils and Wires (only 50miles on them)
Spark plugs
Cleaned MAF
Cleaned ESS
I have catless BHR Mid pipe
Compression test
Cleaned Intake Manifold
Checked SSV (moving freely)
Check ground wires
Deleted VFAD (done 2 yrs ago)
Deleted Air Pump (done a yr ago)
Installed new starter
took off the negative post on the battery for 20 min
pushed the breaks 20times

could my fuel pump or injectors have anything to do with the sputtering and hesitation?