Will engine run w/o 02 sensors connected?

A

ARTTII

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Jan 13, 2004

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Detroit, MI

Apr 13, 2006

#1

• Apr 13, 2006

• #1

I have a fresh EFI setup going into an early model mustang - I have no provision in the exhaust for O2 sensor bungs. I want to start the car and drive it to the exhaust shop to have some welded in - Will the EEC-IV (A9P ECM) '89 mustang harness start the engine without the O2's connected and functioning? If so will it drive okay for me to make it 10 miles to an exhaust shop? thanks.

 

vristang

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Mar 31, 2005

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Apr 13, 2006

#2

• Apr 13, 2006

• #2

I have no direct experience with unhooking the O2s, but I would imagine it would send the computer into a limp cycle.

Only way to know would be to try it. Maybe let it warm up pretty well in the driveway before you try to drive it though. The computer should be looking for a signal from the O2s within a minute or so, maybe sooner I don't remember.

Please let us know if it does work.

jason

 

HISSIN50

"How long does it take to get help in here?

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#3

• Apr 13, 2006

• #3

it should work fine, like Jason said. The puter should go into FMEM mode, but it should run surprisingly well and powerfully.

 

vristang

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Apr 14, 2006

#4

• Apr 14, 2006

• #4

HISSIN50 said:

it should work fine, like Jason said. The puter should go into FMEM mode, but it should run surprisingly well and powerfully.

Click to expand...

Forced into OL?

 

HISSIN50

"How long does it take to get help in here?

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#5

• Apr 14, 2006

• #5

vristang said:

Forced into OL?

Click to expand...

Yeah, it runs in OL, but the default setting is fairly fat.

 

A

ARTTII

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Apr 14, 2006

#6

• Apr 14, 2006

• #6

OK thanks, just wanted to verify that I would not hurt anything attempting this. I still have about a month worth of working on Saturday mornings until I'm ready to fire the motor, I'll bring this post back up to the top with the results then.

thanks for the info

 

Black1987Stang

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Apr 14, 2006

#7

• Apr 14, 2006

• #7

yea it will just be in open loop, I ran almost a year with only the passenger side 02 sensor hooked up, never had any problems but it was stock and burning lots of oil and stuff anyways

 

A

ARTTII

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Jun 15, 2006

#8

• Jun 15, 2006

• #8

So for reference and future searchers:

I have been running my aboved described EFI setup w/o the O2 sensors plugged in/hooked up. No noticeable problem, besides a CEL. Car starts and runs fine without them if you are in a pinch. I plan to get my exhaust modified this weekend or next to be able to do the O2 install...

Hope this helps someone in a search or for general knowledge... thanks guys!

 

9

95bluegt

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Jun 17, 2006

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mooresville N.C.

Jun 17, 2006

#9

• Jun 17, 2006

• #9

if you unhook the 02 sensors your idol will be crap and the whole motor will feel like it is comming apart while driving the car.

 

A

ARTTII

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Jun 18, 2006

#10

• Jun 18, 2006

• #10

95bluegt said:

if you unhook the 02 sensors your idol will be crap and the whole motor will feel like it is comming apart while driving the car.

Click to expand...

funny you post this, i had NO problems at first, idling in the driveway, around the block, etc. but driving to get the O2's installed I turned around and came back, the car is ideling like crap and there is a bog/delay on the throttle - maybe this is contributing to it... will post when I know for sure (after the sensors are installed)

 

R

RickyB

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NJ

Jun 19, 2006

#11

• Jun 19, 2006

• #11

thats odd, unless the car is pretty well modded speed density mode should be able to run the car fairly well w/o any problems