Off-road exhaust = NO check engine Light??

9646GT · 06-20-2003, 12:10 PM

I just had the Mac Prochamber Hipe and Mac cat backs installed yesterday... Love the sound..although kinda loud. Anyway I drove it around quite a bit after getting it on, Id say about 60=70 miles and The "check Engine" light hasnt come on. I even ordered Mil Eliminators thinking I would need them for that. Anyone?

stangt00 · 06-20-2003, 12:27 PM

I put the mac O/R prochamber on mine and nevwer got a check engine light. I dont think it "HAS TO" come on, just the fact that it may come on.

ajcolv · 06-20-2003, 12:34 PM

The CEL won't always come on right away. Sometimes it will be immediately, sometimes in a few hours, days, weeks, etc. You will probably want to put the MIL's on anyways, so this way if the CEL does go on you will know it's most likely not due to the o/r pipe.

9646GT · 06-20-2003, 12:35 PM

Good im happy to hear that.. was thinking my o2 sensors were bad. Well I got the eliminators if I need em

(Update) I was out on a date and driving her home and the CEL came on.. took its sweet ol time. Im going to scan it and make sure thats what it is tho to be sure.

gip99gt · 06-23-2003, 02:04 PM

Just wait, it will come on soon enough....

afeezor97 · 06-24-2003, 02:46 PM

I've had my off-road X-pipe, and Flowmaster cat-backs on for nearly 2yrs now, and still no CEL..... I did get a CEL at first, but after reading the OBDII code, i had a bad O2 sensor. But after further inspection, I pinched the wireharness between the block and tranny when I did my clutch swap... Repaired it, and cleared the computers memory, and the CEL has never come back on after that..

bri32zz · 06-24-2003, 10:59 PM

that is because on the 94-95 models the o2 sensors are before the cats and read the same.

afeezor97 · 06-25-2003, 01:17 AM

Quote:

that is because on the 94-95 models the o2 sensors are before the cats and read the same.

I have a '97 GT. Its had two o2's behind the pre-cats, and two o2's behind the last set of cats. There where 6 cats total.

9646GT · 06-25-2003, 12:28 PM

Quote:

Originally posted by afeezor97
I have a '97 GT. Its had two o2's behind the pre-cats, and two o2's behind the last set of cats. There where 6 cats total.

Yep same here..

bri32zz · 06-25-2003, 01:45 PM

I missread he has a post 95 model---sorry. yeah it is suprising that they have not yet come on. My car only has 2 o2 sensors located before the cats, maybe you engine light bulb is dead

06-20-2003, 12:10 PM	#1
9646GT Registered Member Join Date: May 2003 Location: WV Posts: 24	Off-road exhaust = NO check engine Light?? I just had the Mac Prochamber Hipe and Mac cat backs installed yesterday... Love the sound..although kinda loud. Anyway I drove it around quite a bit after getting it on, Id say about 60=70 miles and The "check Engine" light hasnt come on. I even ordered Mil Eliminators thinking I would need them for that. Anyone?

06-20-2003, 12:27 PM	#2
stangt00 Registered Member Join Date: Dec 2002 Location: Philadelphia PA Posts: 143	I put the mac O/R prochamber on mine and nevwer got a check engine light. I dont think it "HAS TO" come on, just the fact that it may come on. __________________ 2000 GT 80mm Pro-M mass air, 24lb injectors, 75mm BBK T/B, K&N Filter Cold Air, 1/2" Phenolic intake spacer, Underdrive Pulleys, Dyno Tuned Autologic Chip, FMS Shorty Headers, Mac Prochamber 2 1/2" Off Road H pipe, 2 Chamber Flowmasters, Steeda lowering springs. Steeda Tri-Ax Short Throw shifter, Steeda Power slot rotors w/ Hawk Pro pads, 3.73 FRP Gears. Headwork and Comp cams install in progress.

06-20-2003, 12:34 PM	#3
ajcolv Registered Member Join Date: Oct 2002 Location: Utah Posts: 58	The CEL won't always come on right away. Sometimes it will be immediately, sometimes in a few hours, days, weeks, etc. You will probably want to put the MIL's on anyways, so this way if the CEL does go on you will know it's most likely not due to the o/r pipe. __________________ -Aaron "Lita" 97 Mustang GT Vert -------------------------------------- k&n, air silencer removed, Magnapack cat-back, BBK o/r h-pipe, Ford red front calipers

06-20-2003, 12:35 PM	#4
9646GT Registered Member Join Date: May 2003 Location: WV Posts: 24	Good im happy to hear that.. was thinking my o2 sensors were bad. Well I got the eliminators if I need em (Update) I was out on a date and driving her home and the CEL came on.. took its sweet ol time. Im going to scan it and make sure thats what it is tho to be sure. __________________ 1996 GT 4.6 Last edited by 9646GT; 06-21-2003 at 12:33 AM..

06-23-2003, 02:04 PM	#5
gip99gt Registered Member Join Date: Mar 2002 Location: Cedar Hill, Tx Posts: 19	Just wait, it will come on soon enough.... __________________ 99 Triple Black 5-Speed GT MODS: Flowmaster Mufflers * MAC O/R H Steeda Pulleys Steeda Timing Adjuster * Dallas Mustang Speed Cal * Dallas Mustang MIL's * FRPP 4.10 Gears * FRPP 70mm Throttle Body * Ford C Springs * Pro-M 80 mm w/filter * S-E-Racing Intake Spacer * Nitto DR's (Street) * BFG DR's (Track)

06-24-2003, 02:46 PM	#6
afeezor97 GRNSNAK Join Date: Jun 2002 Location: Slidell Louisiana Posts: 65	I've had my off-road X-pipe, and Flowmaster cat-backs on for nearly 2yrs now, and still no CEL..... I did get a CEL at first, but after reading the OBDII code, i had a bad O2 sensor. But after further inspection, I pinched the wireharness between the block and tranny when I did my clutch swap... Repaired it, and cleared the computers memory, and the CEL has never come back on after that.. __________________ 1997 Cobra SVT & 2012 Shelby GT500

06-24-2003, 10:59 PM	#7
bri32zz Registered Member Join Date: Aug 2002 Location: Canton GA Posts: 216	that is because on the 94-95 models the o2 sensors are before the cats and read the same. __________________ My CAR IS GONE R.I.P----I miss YOU 331ci, 69 Windsor heads ported and shaved , Trick Flow-Intake ported,JE blower pistons, Custom cam 542 lift, 1.73 rrs, Equal length headers, BBK Hi-Flow cats, Hurst shifter, 3:73 gears, Tremec 3550 tranny,Lakewood drag suspension-90/10 in front and 50/50 in the back. Lakewood traction bars. Edelbrock 70mm tb, K&N filter, Kirban fuel reguator, Custom sub-Frame connectors,83 lb squirters, powerdyne blower with 12psi pulley, http://www.pumpoperators.com/brian/ Rice Haters Club Member #82 My wife is AWSOME!!!!!!!!

06-25-2003, 01:45 PM	#10
bri32zz Registered Member Join Date: Aug 2002 Location: Canton GA Posts: 216	I missread he has a post 95 model---sorry. yeah it is suprising that they have not yet come on. My car only has 2 o2 sensors located before the cats, maybe you engine light bulb is dead __________________ My CAR IS GONE R.I.P----I miss YOU 331ci, 69 Windsor heads ported and shaved , Trick Flow-Intake ported,JE blower pistons, Custom cam 542 lift, 1.73 rrs, Equal length headers, BBK Hi-Flow cats, Hurst shifter, 3:73 gears, Tremec 3550 tranny,Lakewood drag suspension-90/10 in front and 50/50 in the back. Lakewood traction bars. Edelbrock 70mm tb, K&N filter, Kirban fuel reguator, Custom sub-Frame connectors,83 lb squirters, powerdyne blower with 12psi pulley, http://www.pumpoperators.com/brian/ Rice Haters Club Member #82 My wife is AWSOME!!!!!!!!

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