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  • SN95 4.6L Mustang Tech

[HELP] Car surges after switch of midpipes

  • Thread starter Thread starter Twista
  • Start date Start date Jun 2, 2009

Twista

Active Member
May 7, 2004
510
2
29
@ the z00 in chicago
Jun 2, 2009
#1
  • Jun 2, 2009
  • #1
I have stock headers, mac o/r H and mac catback. Already resetted the cpu by unplugging the battery.

So, i switched midpipes many times before and this is 1ST time this has ever happened.

So, i had to swap my mac o/r H pipe out for my mac catted h and everything went as planned expect the gasket wasn't holding like it should. Anyways, the car developed a nasty leak, but i took it for the emission test anyway and passed.


Fast forward to today i went and brought a new gasket from ford and put back on my Mac O/r H. The surging problem is still there

It happens when you take off from a stop. The 1st couple rpms the car is like bogging down and surging and you can hear it and feel it.

Downshifts than accelerating it the car is normal.

The only thing i messed with was the rear o2 sensors.

Does this sound like an exhaust leak somewhere? If so, i cant hear this baby.
What could a exhaust leak damage? The o2 sensors???

Damn it.!

Thanks

edit: while this was happening with the catted midpipe on.. there was no MIL OR CEL ON. NO CODES
 

squeak93

15 Year Member
Jun 2, 2005
2,277
368
164
Joplin, Missouri
Jun 2, 2009
#2
  • Jun 2, 2009
  • #2
An exhuast leak before the upstream o2's will cause the puter to think its lean (unmetered air in the system) and there fore it will actually inject more fuel. That could cause a bucking issue down low.

What codes is it throwing now if any?
 

Twista

Active Member
May 7, 2004
510
2
29
@ the z00 in chicago
Jun 2, 2009
#3
  • Jun 2, 2009
  • #3
squeak93 said:
An exhuast leak before the upstream o2's will cause the puter to think its lean (unmetered air in the system) and there fore it will actually inject more fuel. That could cause a bucking issue down low.

What codes is it throwing now if any?
Click to expand...

Not sure of the codes, but im sure im throwing the no cat code. So i will take apart the mid again and try re-seating it.

I pray this is the problem.

ty
 
J

jomull55

New Member
May 20, 2007
202
0
0
lucas, OH
Jun 2, 2009
#4
  • Jun 2, 2009
  • #4
before you tear it apart check and make sure your o2 sensors are plugged in well and making good contact
 

Twista

Active Member
May 7, 2004
510
2
29
@ the z00 in chicago
Jun 2, 2009
#5
  • Jun 2, 2009
  • #5
re-did the midpipe and still got the same problem =[ Its hesitates so bad down low @ random times.

**** man.
o2 sensors are installed fine and plugged in good =[ damn it
]
this sounds like my problem exactly: http://answers.yahoo.com/question/i...dYM3M34jzKIX;_ylv=3?qid=20070905185422AAaTuEy

=[
 

squeak93

15 Year Member
Jun 2, 2005
2,277
368
164
Joplin, Missouri
Jun 2, 2009
#6
  • Jun 2, 2009
  • #6
Link is blocked.... What does it say?
 

Twista

Active Member
May 7, 2004
510
2
29
@ the z00 in chicago
Jun 2, 2009
#7
  • Jun 2, 2009
  • #7
squeak93 said:
Link is blocked.... What does it say?
Click to expand...


I have a '96 chevrolet pickup question?
I have a '96 chevrolet half ton 2wd with a vortech 5.0 in it. It had trouble codes stored in it and then when I had it looked at the guy erased them all and told me to replace the both bank O2 sensors so I did and the truck ran a little better, but it still hesitates under hard accelleration like it is starving for fuel. Under regular accelleration it seems normal. So I called the guy back and he said that he meant the one downstream from the cat. I want to know any ideas and would the 1 O2 sensor make it fall on it's face so bad during hard accelleration? I have already checked for a plugged cat. and I have replaced the fuel filter. Does a failed O2 sensor cause a lean condition?

* 2 years ago



Best Answer - Chosen by Voters
Yes, bad O2 sensors will cause your vehicle to hesitate and run poorly... replace the suspected sensor, you wont believe the difference it makes.

* 2 years ago
Click to expand...
..........
 

Pearl02

Member
Nov 27, 2004
496
0
16
Kansas City
Jun 2, 2009
#8
  • Jun 2, 2009
  • #8
There could be damage to an 02 sensor or the connecting wire. I'm surprised you are showing no codes. I just installed my first midpipe and I can see where some damage could have been done. Try to pull codes if there's any. Pearl02.
 

Twista

Active Member
May 7, 2004
510
2
29
@ the z00 in chicago
Jun 3, 2009
#9
  • Jun 3, 2009
  • #9
I just brought 4 new sensors, but there being shipped. So what would happen if i unplugged the sensors and test it? Or does the car need the sensor for it to operate somewhat properly?
Just wondering if i unplug the 2 front ones would the car drive normal if they are faulty?
 

squeak93

15 Year Member
Jun 2, 2005
2,277
368
164
Joplin, Missouri
Jun 3, 2009
#10
  • Jun 3, 2009
  • #10
If you unplug the front sensors you take away the cars ability to "adaptive learn". That means it cannot make on the fly fuel adjustments to get the optimal performance and mileage. The rears will not cause what the link above eludes to. The rear o2's Simply tell the puter if the cats are working or not, w/o cats or mils you will get a rear o2 code..... That will not affect performance whatsoever. With that said, if your fronts are bad if can cause all sorts of crazy stuff to happen. Not likely that both fronts went at the same time unless you caused damage to them when removing and reinstalling.

Never hurts to buy new o2's but I fear this likely won't solve ur issue.
 

Twista

Active Member
May 7, 2004
510
2
29
@ the z00 in chicago
Jun 3, 2009
#11
  • Jun 3, 2009
  • #11
I think i got the problem pin pointed, just i cant access the sensor. So i guess driving with the bad exhaust leak on the passenger side somehow sent the soot to my air flilter which is black and gunky nasty. So, with that said.. my MAF has to sooted to hell. I brought some MAF cleaner but i have to buy a t-20 female torx =[
 

squeak93

15 Year Member
Jun 2, 2005
2,277
368
164
Joplin, Missouri
Jun 4, 2009
#12
  • Jun 4, 2009
  • #12
Not sure an exhaust leak can dirty up an air filter. But the would def cause the issues your talking about.
 

Twista

Active Member
May 7, 2004
510
2
29
@ the z00 in chicago
Jun 4, 2009
#13
  • Jun 4, 2009
  • #13
squeak93 said:
Not sure an exhaust leak can dirty up an air filter. But the would def cause the issues your talking about.
Click to expand...

well i had no gasket on the passenger side which is required or else it would leak bad.

I just brought the torq so will clean the MAF today and pray it helps
 

squeak93

15 Year Member
Jun 2, 2005
2,277
368
164
Joplin, Missouri
Jun 4, 2009
#14
  • Jun 4, 2009
  • #14
Yea no gasket will cause one big leak but how the hell did it dirty up ur air filter? Those two are a long ways apart. Is it an engine bay filter or is in the fenderwell. If your filter is that dirty then your whole engine bay must look like a chimney.....
 

Twista

Active Member
May 7, 2004
510
2
29
@ the z00 in chicago
Jun 4, 2009
#15
  • Jun 4, 2009
  • #15
=[ nope that didnt fix the problem. So, next ill check the throttle body and clean it. Than the spark plugs and wires..

Than the fuel filter, but that was changed about 3 years ago =]
 

squeak93

15 Year Member
Jun 2, 2005
2,277
368
164
Joplin, Missouri
Jun 4, 2009
#16
  • Jun 4, 2009
  • #16
DON'T CLEAN THE T/B.........

It has a coating on it that most cleaners will take off and cause horrible idle issues..... fyi. wipe it with a dry rag at best..(or use a t/b safe cleaner).
 

Twista

Active Member
May 7, 2004
510
2
29
@ the z00 in chicago
Jun 5, 2009
#17
  • Jun 5, 2009
  • #17
If i bog the engine on purpose by shifting to a high gear @ 2 low speed.. the car REALLY and i mean REALLY sputters and hesitates.

Does this ring a bell to anyone?
 

Twista

Active Member
May 7, 2004
510
2
29
@ the z00 in chicago
Jun 6, 2009
#18
  • Jun 6, 2009
  • #18
just got done fixing the problem I changed the spark plugs/wires and the problem is gone.
 
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