Bad Cat lead to MPG loss and check engine light?
08-16-2009, 10:15 PM
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Year: 1998
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Engine: 4.0L w/ AFE stage 2, bored TB
Bad Cat lead to MPG loss and check engine light?
Hey guys I got a Magnaflow muffler put on a while back and they told me my cat was bad.
Fast forward to today and for the last few weeks my check engine light will come and go. No real noticable problems, checked all the fluids and everythings fine. So, the other day I make a turn and the Jeep jumps RPMs a few times like bad gas. Prolly all it was but it just added to my suspicion.
Also, noticed a few MPG loss and little power loss from the norm with 4:10s and 35s lol. So Im looking at a new Magnaflow high flow to replace it.
So will a bad cat set off the check engine light here and there? Any other ideas?
Also, with AFE intake, bored TB, high flow cat, and the muffler would I probably need bigger injectors? My uncles TJ did after all this. Thanks
Fast forward to today and for the last few weeks my check engine light will come and go. No real noticable problems, checked all the fluids and everythings fine. So, the other day I make a turn and the Jeep jumps RPMs a few times like bad gas. Prolly all it was but it just added to my suspicion.
Also, noticed a few MPG loss and little power loss from the norm with 4:10s and 35s lol. So Im looking at a new Magnaflow high flow to replace it.
So will a bad cat set off the check engine light here and there? Any other ideas?
Also, with AFE intake, bored TB, high flow cat, and the muffler would I probably need bigger injectors? My uncles TJ did after all this. Thanks
08-16-2009, 10:34 PM
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Year: 1996
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Bad cat can cause the following , high mpg, check eng light, loss of power, overheating, stalling, and more. 35" tires can also cause high mpg and sluggishness, but in this case get a cat. Re-injectors I can't help.
) my check engine light came on the first time i started it up afterwards
08-17-2009, 12:09 AM
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Do the CEL check by turnin the ignition on 3 times without cranking it and it'll flash codes in the odometer readout. Post the numbers and we can see whats goin on.
When my cat stated to go i got aweful mpg and sumwhat lost performance til it compeltely clogged up, then it would barely run. Since then I've gutted the cat, traded the mud tires Wednesday for sum 225/70-15's and I'm getting a mixed driving MPG of 26MPG. Go figure
When my cat stated to go i got aweful mpg and sumwhat lost performance til it compeltely clogged up, then it would barely run. Since then I've gutted the cat, traded the mud tires Wednesday for sum 225/70-15's and I'm getting a mixed driving MPG of 26MPG. Go figure
08-17-2009, 12:12 AM
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Year: 1998
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Do the CEL check by turnin the ignition on 3 times without cranking it and it'll flash codes in the odometer readout. Post the numbers and we can see whats goin on.
When my cat stated to go i got aweful mpg and sumwhat lost performance til it compeltely clogged up, then it would barely run. Since then I've gutted the cat, traded the mud tires Wednesday for sum 225/70-15's and I'm getting a mixed driving MPG of 26MPG. Go figure
When my cat stated to go i got aweful mpg and sumwhat lost performance til it compeltely clogged up, then it would barely run. Since then I've gutted the cat, traded the mud tires Wednesday for sum 225/70-15's and I'm getting a mixed driving MPG of 26MPG. Go figure
08-17-2009, 12:21 AM
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Year: 1998
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Engine: 4.0L w/ AFE stage 2, bored TB
So just turn the key and crank it 3 times in a row but dont let it start up? It will just flash the codes? If it flashes codes theres my problems or what?
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08-17-2009, 12:23 AM
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Year: 1998
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Engine: 4.0L w/ AFE stage 2, bored TB
What Im really concerned with is if I will need to get new injectors since ill be pulling and pushing a lot more air than stock? Anyone have experience on this? Thanks
08-17-2009, 12:43 AM
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On-Off-On-Off-On, count the blink engine light wait for pause count again
ending is 5-5
08-17-2009, 12:43 AM
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08-17-2009, 07:20 AM
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Year: 1998
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Engine: 4.0L w/ AFE stage 2, bored TB
no turn your key like your going to start it but dont let it start...repeat two more times and then sit and watch the number of flashes. Count how many times the check engine lighths.
On-Off-On-Off-On, count the blink engine light wait for pause count again
ending is 5-5
On-Off-On-Off-On, count the blink engine light wait for pause count again
ending is 5-5
08-17-2009, 09:23 AM
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hey not to thread jack but im getting my new catback in the mail but with all this gutting cat talk now i want to do it, i have no emission reqs to deal with so do i just take it off and empty it with a screw driver or something? pros and cons of doing it? and does the check engine light go away after doing it?
08-17-2009, 09:33 AM
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Year: 1996
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hey not to thread jack but im getting my new catback in the mail but with all this gutting cat talk now i want to do it, i have no emission reqs to deal with so do i just take it off and empty it with a screw driver or something? pros and cons of doing it? and does the check engine light go away after doing it?
08-17-2009, 09:54 AM
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hey not to thread jack but im getting my new catback in the mail but with all this gutting cat talk now i want to do it, i have no emission reqs to deal with so do i just take it off and empty it with a screw driver or something? pros and cons of doing it? and does the check engine light go away after doing it?
08-17-2009, 12:57 PM
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Year: 1998
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Engine: 4.0L w/ AFE stage 2, bored TB
Tried the CEL test. CEL came on for just a sec then disappeared. No codes?
Never done it before so I'm not sure...
Never done it before so I'm not sure...