I have an 03 expedition when the heat is turned on and u are idling the rooms jump every few seconds.. I've heard maf sensor or tps any help would be great thanks

most bad cat converters do not affect idle as there is little gas flow problem at that speed
different at speed or full throttle
try using a scan tool to reset the ECM after all of the new parts
the sensors (O2 ) are not the faulty units as listed by the code p 2198 which are the heated oxygen sensors in the exhaust manifolds before the cat converters -- fault stuck rich
AS these senors (HO2S) report the gas composition to the ECM to adjust air /fuel ratio it is very possible that these being faulty , the ecm is allowing extra fuel into the engine and in effect running on choke
Using the throttle to idle suggests that the problem is air /fuel mixture for and idling engine and I would be investigating that area as the problem

sure, when unplugged the MAF , the PCM goes to limp home
and mimics the dead or missing MAF.
one reason, of many
is the AFR is lean, with maf present
then you remove MAF and the mimic goes horrid rich. (normal effect)
this huge rich hides the true cause of horrid lean.

see? 2 wrongs, make a right in this case.

its a 97, why are you scan too free.
connect it and see it fail. and why?
see all sensors. here. same engine, same all.

http://www.fixkick.com/ECU/Authority/A_Full_OBD2_scan.html


air leaks on this engine cause, lean.
a dirty mAF causes, lean. (clean it with carb spray 1foot away never close up)
clogged injectors cause, lean.
low fuel pressure causes lean.

if you put all the parts back and scan it
you'd see that.
you'd see the 0xysensor (Front) stuck lean B1S1. bank 1 sensor 1
ignore B1S2.

try a new oxysensor front. first. so the scan tool can see true facts.

on a good engine, the 02 swings at idle
if that fails , i jump over that like at tick on a hound dog.
finding car parked and idling hot AFR issues, is easy with any scan too.
the EFI must be in closed loop at idle, hot, MUST.
is it>?
does the maf read right at idle, ?
1.5-4.0 grams per second
or MAF output pin volts of. 1.7-2.0 volts
if the voltage is good ITS NOT THE MAF, its LEAN AFR.
AIR FUEL RATIO IS AFR. lean means FUEL STARVATION.

if you gun the throttle
the maf goes higher.
3v or 20grams/second.

here is me driving see MAF hit 55 grams/ a second.
Hills. do that.
the more HP the more Grams /per second, until max engine torque is hit. and RPM max HP.

here is live data plot of a 96 MAF

http://www.fixkick.com/my96-16v/MAF-TPS.JPG

the blue line is THROTTLE ANGLE> im driving aggressive as heck.

if the maf tests good, its not the MAF>
its easy to test.

Clean your throttle body and map/maf sensor. If that doesn't work you may have a bad iac sensor (idle air control sensor)

vacuum line possibly on the tps sensor there is a arm with spring maybe accidently installed wrong

The first thing you need done is a scan of the TCM for fault codes

The surging usually comes from the IAC hunting to maintain a stable idle. usually your symtoms occur from a vacuum leak of some sort. plastic intakes are sometime found to be cracked from heat embrittlement. spray the top of the engine with brake clean when running. if the idle changes when spraying in a certain area you are locating the vacuum leak. the idle will change when the engine sucks in the brake cleaner.

Hello and welcome to FixYa!

As a first course of action, I strongly suggest that you remove the positive battery connector of the car and let it sit for at least 5mins. then reconnect it again. Turn the engine on and observe is it will sit on the right idle.

If the problem still persist, then you may facing two things. First is, a faulty MAF (mas air flow) sensor. If the MAF sensor is faulty, you'll have irregular vacuum supply which may cause an erratic idle. You will need to replace it to resolve the issue.

Second will be, a faulty TPS (throttle position sensor). If the TPS is faulty, an unusual idle may occur as well. They really tend to fail when worn out and I suggest that you have it replaced if necessary.

Hope this helps and thank you for using FixYa! Have a good one!

Hi and welcome to FixYa!

Looks like that you have a faulty TPS (throttle position sensor) or MAF (mass air flow) sensor. If one of the sensors are faulty you'll have erratic idle. Have it replaced to resolve the problem.

Hope this helps and thank you for using FixYa! Have a good one!

Spray the Throttle Plate with CRC Throttle Body Cleaner

Not better--Test the TPS Sensor and replace, only if it
fails a test

Clean the MAF Sensor with CRC MAF Cleaner

You have an electronic throttle control motor,
if the throttle plate sticks ,it goes into ETC Failsafe and shuts off
or only goes 6MPH

Check IAC sensor and TPS and MAF sensors if IAC is ok. IAC will amke your idle go up and down all crazy and cause stalls when slowing down or releasing throttle but TPS and MAF also can effect this.