check engine light on
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Junior User
Joined: Jan 2004
Posts: 99
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From: ohio
check engine light on
Hi. I have the check engine light on and had tested and was told i have code 172. Can anyone help? The engine is idleing rough, and gas mileage is 12 mile per gal.
THANKS IN ADVANCE OLDMANBERGIE
THANKS IN ADVANCE OLDMANBERGIE
Post Fiend
Joined: Apr 2005
Posts: 5,720
Likes: 5
From: Washington state
what year Aero, 172 indicates 3 letter codes from OBDI EEC-IV pre '96 system
172=HEGO sensor circuit indicates lean.
1. Failed O2 sensor...if more than 50k miles on present one replace
2. with the rough idling, look for a vacuum leak with a spray can of throttle body cleaner or carb cleaner, spray vac. tubes and fittings....engine smoothes out=leak found
3. IAC dirty and sticking wide open
clean or replace
4. MAF dirty and giving false air flow readings
clean or replace
5. Failed ECT sensor giving false hot coolant signal
replace
do 1 step at a time.....disconnect neg bat. lead after each to reset KAM in ECU and drive for 10-20 miles checking for improvement
172=HEGO sensor circuit indicates lean.
1. Failed O2 sensor...if more than 50k miles on present one replace
2. with the rough idling, look for a vacuum leak with a spray can of throttle body cleaner or carb cleaner, spray vac. tubes and fittings....engine smoothes out=leak found
3. IAC dirty and sticking wide open
clean or replace
4. MAF dirty and giving false air flow readings
clean or replace
5. Failed ECT sensor giving false hot coolant signal
replace
do 1 step at a time.....disconnect neg bat. lead after each to reset KAM in ECU and drive for 10-20 miles checking for improvement
Thread Starter
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Junior User
Joined: Jan 2004
Posts: 99
Likes: 0
From: ohio
I did disconnect battery for aprox 15 min. Still have check engine light on after running about 10 min. Also code 542?
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Postmaster
Joined: Sep 2003
Posts: 4,452
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From: Southern California
All I can say is that code 542 has to do with your fuel delivery. Check your fuel pressure regulator and your fuel pump.
Also, check and make sure the O2 sensor wires are not shorted to the block.
Good luck
Also, check and make sure the O2 sensor wires are not shorted to the block.
Good luck
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Post Fiend
Joined: Apr 2005
Posts: 5,720
Likes: 5
From: Washington state
code 542= (O,M) Fuel pump circuit open, bad ground or always on - - Power / Fuel Pump Circuits
indicates failed or faulty wiring or fuel pump
you will need the fuel system wiring diagram of your year of Aero to troubleshoot
do you still have code 172?
indicates failed or faulty wiring or fuel pump
you will need the fuel system wiring diagram of your year of Aero to troubleshoot
do you still have code 172?
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