Last week i changed my right caliper (bc it was stuck) front brakes and rotors. Regardless of that, my acceleration has been so bogged down, that it struggles.

I have checked the oil and trans fluid, which is fine. The car is driving real rough. I do have a broken bushing on the pass side control arm, but i dont know if it would make the drive rough. The engine sounds like it has little oil in it, but i check it everyday, in which it has a good amount (i hate the confusing dipstick too)

I dont know if it has EGR or PCV issues, or even if my coils are shot. No clue. NO CEL.

Anyone relate ?

 

hmm...clogged precats/main cat !?!??
even though that'd trigger o2 sensor codes

 

Both precats have been cleaned out. Only cat i have is rear. O2s have been replaced. I think i might need to clean the MAF...i have 188k on the car now

 

Hmm, is your idle real rough? If the idle is real rough and the car struggles it could be coils, but there are a ton of possibilities. You should be able to tell if its a suspension problem or an engine problem. How many miles are on the car? Are the spark plugs good and gaped properly?

 

I replaced the plugs about a year ago. They have been driving fine ever since i installed them. The coils might be something i might suspect, but there are no misfires, knocks etc.

Idle is fine as well, just throttle response is complete sh#t and car drives real rough and hard. Feels like a 3 cylinder

 

Bad injector?

Your MAF is probably not too bad..Unless you have had an oiled intake filter for long period of time it could get a little cloggy, I cleaned mine for the first time at 172k and didn't really feel much difference and I used K&N filter.

Try running Seafoam

 

tps, timing chain jumped a tooth or a poor fuel pump.

sweep the tps and do a fuel volume and pressure test thats where i would go at least

 

What about the rear POS cat? It clogs up just the same. Punch that **** out and see what happens.

Of course, MAF is always the highest suspect.

 

you changed your brakes and nobody thought to mention they are probably sticking? Give them a look over

 

My guess is fuel....No CEL and it idles fine but struggles when you give it gas?

Change your fuel filter (it's quick and cheap - get the filter and fuel-tank o-ring from courtesyparts.com). If that doesn't help, I'd suggest finding a local shop that will service your injectors. You should be able to find a place that'll make them like new for around $100 if you bring the injectors in, or buy a used set from the classifieds here. Lots of people parting out - these cars are 10+ years old now

 

All good possibilities mentioned above, def check those out.

 

this is where I would start as well

 

K.S. (knock sensor)

 

I do want to point out for others with stock cats that it DOES NOT have to throw codes for the precats. They can and will toast your motor and no CEL will come on. Rear cat of course can never trigger a CEL.

 

lift tires off the ground and spin by hand, then have someone press the brakes and as soon as they release them the tire should spin freely by hand again, otherwise brakes are sticking.

Tps not set correctly, look in a haynes manual to see how to set the idle set point for the TPS, I had a funky accel problem and this fixed it.

Have you ever changed your plugs? what is in there now?

Knock sensor will also do this.

 

I did the wheel thing before, and it was free, with no rotor rubbing.

Have not messed with TPS.....

Plugs were all replaced with the required platinum plugs OEM, less than a year ago.

I havent checked KS...but doest it affect that much

 

Dude get some Maf cleaner and clean ur Maf... There is a thread somewhere on here on how to do it... I had the same problem and after cleaning my maf the car ran amazing. Can't hurt to do it, takes 10 mins and about $5

 

yes.

a knock sensor will make a difference and wont always throw a code, i would probe your TPS as well, it wont throw a code if its in spec, but still could be out.. the FSM says anywhere (dont quote me on the exact voltage, double check the FSM) from like .20 -.84 .. when i had mine set around .43, i had what felt like bad performance, but it also affected my shifting (auto), it felt really sloppy. i bumped it up to .75 and it made a huge difference. i even noticed that my shifts are alot firmer and it made my 2-3 sloppy flairing cold shift almost dissapear (mind you im not hard on it when its cold) i would def. check those being its five mins to remove those from the list.

i also read that alot of the early 5th gen maximas TPS were not set properly from factory ( i think i read that in the "owens family" TSB's.)

 

Had the brakes checked out again, with no stick. I just cleaned the MAF and havent really driven it anywhere yet. It still feels rough. I have a new KS that i will put in when i change my front and rear valve cover gaskets (probably friday night)

I dont know what to do next. I guess i will try to clean the TB again. How do i adjust the voltage on that thing ?

Thanks

 

Ok,

So cleaning the MAF actually ended up working. I jumped from 24 mpg to around 26-27 mpg at the moment. Drive seems a bit smoother, idle is normal. Car still feels rough, but we will see what happens once KS is changed

 

Cleaning the throttle body "AGAIN" ?

when did u clean it the first time? right Befor this happened? Did u disconnect any vac lines u may have forgot to reconnect? Like one to the FPR, if its only on acceleration, the vaccuum might not be increasing in p.s.i. with the increase in throttle.? Forget to put the gasket back in? Was it damaged?

Lastly, i dont know what year your car is, but i hope it isnt a 3.5 and u have already cleaned the TB and buggered it.

 

Hope you find the culprit so you get the performance back......