Limp mode help
 

2004 rx8 keeps going into limp mode. We have put new spark plugs and spark plug wires. New MAF sensor a new front 02 sensor and all new ignition coils. Not sure what to do next. Will the rear 02 sensor cause it to go into limp mode? :ugh2:

What limp mode is it? There is more than one. Each with it's own behavior and cause.

H02S BANK 1 SENSOR 1 HEATER

CYLINDER 2 MISFIRE

Those are the 2 codes it is throwing

Which limp mode is it going into? Can you describe it?

It will run then no power can't go over 20 miles an hour and can't get any rpm s out of it.

I'm trying to help you, but you aren't being very clear here. The Front O2 heater code shouldn't come back now that you replaced the sensor. The misfire has lots of possible causes (https://www.rx8club.com/series-i-tec...t-here-222280/)

Do you know that you are in an ECU commanded limp mode? or do you just have problems making power and think that it's a limp mode? Each limp mode is specific ECU commanded behavior to change the rev limits, remove ability to control the throttle, restrict throttle usage, change to emeregency fuel maps, etc... The more specific you can be, the better we can help you.

All I know is the codes it gave me p0302 01/04. And P0030 02/04.
I just replaced the front 02 sensor day before yesterday. The car ran great all day yesterday and todayI ddidn't even make it out of my driveway before I had no power. I can push gas pedal to the floor and have basically nothing. You can unhook battery for awhile and it might run and it might not. Not sure if that helps or not.

Unfortuantely, not really.

So, start with the basics. You got plugs, wires, and front O2.
Have you changed the coils? (they only last 20,000-30,000 miles reliably, by 30,000 you are already down ~15% power)

Have you cleaned the e-shaft sensor and reset it's electronic profile?

Was the MAF you bought a legitimate one? (there are definitely faulty or subpar brands out there that cause problems)

Have you tested for a vacuum leak?

Have you checked AFRs when it stumbles to see if it's stumbling from being too rich or too lean?

Yes coils have been replaced. MAF was purchased from Summit brand JET. Have not checked to see Iif it's to lean or rich. Have not checked e shaft sensor or for vacuum leaks. I will do that tomorrow and see what she does. Thanks so much

Vacuum leaks have been checked for and there aren't any. My yes it is an ECU limp mode. I will clean e shaft sensor and see if we are running either to lean or rich in the morning.

Metering Oil Pump

Most common limp mode.....no code often


Remove intake tube at throttle....reset the ECU ( remove battery -ve and push on brake pedal)

start car.....if throttle moves normally and it revs normally for approx 5 sec...and then throttle stops responding properly......it is likely the MOP

Sometimes the positioning switch can be tweaked a little either way.....and it will work correctly after

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