Throttle position sensor Vs Mass Air Flow

[bryan.urieta]

Anyone ever had problems with these two,I just replaced the MAF but im still having problems.

 

 

Car turns off when I turn it on,

Rough idle

Car stalls and bucks shifting gears

Idle goes from 500-1000 rpm jogging

[Precise1]

What does the OBD2 system have to say?

 

B

[bryan.urieta]

The who what ?

[Precise1]

On Board Diagnostics 2 system, all US vehicles 1996+ have it (might be something different for the brand new car though). Basically, there is a port underneath the dash on the drivers side that you plug a reader into. A basic reader will tell you of any stored codes and allow you to clear them, a fancy one will tell you a lot of real time information as well.
The stored codes can be very specific as to the fault source, so it is always a good thing to check first.

A cheap reader is about $50, and some automotive parts places like Pep Boys (and I think Autozone) will read your codes for you for free in hopes of selling you something, obviously.

 

Go to the Garage section and download a copy of the 2003 Factory Service Manual from the link posted in the pinned thread. Section EC will have a list of all the fault codes along with recommended diagnostic/repair procedures.

 

B

[fixinto]

check the easy stuff first. go around your intake boot and make sure there isnt any vacuum leaks. "cracked plastic tube running to your throttle body." IF the boot is ok, there are other sources for leaks. For instance, if it only stumbled and ran rough with your foot on the brake, i would say your brake booster has an air leak. Another possible source is your PCV valve stuck open. OR your EGR valve is stuck open. I know that is a lot of stuff to look at, but usually a vacuum leak will cause rough idle, stalling, wondering idle, and so on. If under full throttle it feels ok or normal than more than likely it is a vacuum leak somewhere. or a faulty O2 mis reporting air / fuel I hope this gives you some direction without spending $ on it.

 

 

Pat