bblemans

My Maxima all of a sudden will not accelerate normally. It will rev up but not increase speed and it doesn't feel like it's slipping. Anything more than a little throttle and it will act up. It has no power up hill and almost comes to a stop on steep ones. In park I can rev it to 3000 rpm and it will start to stumble there for a couple of seconds and then continue to rev up but the engine starts to detonate (ping). I replaced both rear ABS sensors and then removed ABS fuse and no improvement. Car has 130,000 on it and has CVT trans. Thanks in advance for any help you guys can give me!
John.

eastsidemoon

Any check engine light?

bblemans

No light and no codes.
And all cat. converters replaced 40,000 miles ago.

po8pimp

sounds like a cam shaft position sensor problem

bblemans

Thats where I was leaning to next. Do you think the crankshaft sensor is a possibility as well? Thank you for your input.

bblemans

Update: Replaced both cam sensors and the crank sensor. No change. Driving the car if you go to accelerate it gets to around 3000 rpm's and stumbles and won't go past that and won't speed up. If I floor it it will get to around 4300 rpm's and detonate like crazy. when it does the stumbling it feels as if the brakes are on but they are not. I ease up on the gas then it will start to slowly pick up speed.

maxiiiboy

This sounds like a typical VSS (Vehicle Speed Sensor) problem.

NIKV69

A cam sensor would have thrown a code as would any sensor failure.

rustymaxima07

The ABS sensors will not show any engine light. Feels like the tranny just disconnects as your accelerating. Sticks at 3500 rpm super slow acceleration. You cant just pull the fuse you need to disconnect both sensors near the center of the rear end. Your speedo will still work this way.

Maybe it could be a MAF messing up the fuel map, but it would probably stall a lot if it was.

rustymaxima07

Did you clean up the rust where the ABS sensors mount. You may have to replace the hubs as well, that's what happened with mine. It just cropped up again a few days after I replaced sensors. Any slight difference in signal and limp mode activates.

bblemans

PROBLEM SOLVED!!
Finally gave up and took it to a good shop.
Turns out not all of my cat converters were changed as I thought.
Only the pre-cats were and the rear one was not and it was plugged solid.
Car now has more power than it ever has.
Thank you to everyone for all the advice!