damn check engine lite keeps coming on
#1
08-21-2006, 08:26 PM
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damn check engine lite keeps coming on
hi there propably mod related but when i installed the cai i removed the neg bat term as told worked great all was good then i installed headers hi flow cats and the cat back exaust removed the neg terminal as told and stayed off for about a week and then turns back on.I want to get the code but will the snap on diagnostic machine be able to read the code ? any other ideas are welcome p.s keep in mind the oil dipstick is still not solidly in place yet .
#2
08-21-2006, 08:54 PM
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RE: damn check engine lite keeps coming on
Something to look into:
I have seen where the high flow cats are not that efficient. When the computer does it's daily checks, the secondary o2 sensor picks up unspent fuel in the exhaust past the cats. When it see's this it throws a code. There are o2 simulators out that plug into the harness and fool the computer. I think GSM sells them.
Mike
I have seen where the high flow cats are not that efficient. When the computer does it's daily checks, the secondary o2 sensor picks up unspent fuel in the exhaust past the cats. When it see's this it throws a code. There are o2 simulators out that plug into the harness and fool the computer. I think GSM sells them.
Mike
#3
08-21-2006, 09:21 PM
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RE: damn check engine lite keeps coming on
An alternative may be to install a shim that will place the O2 sensor further away from the main flow of the exhaust.
Get "18mm sparkplug non-fouler" from AutoZone PN 42009, and drill out the bottom of it with a 1/2 bit so the end of the O2 sensor will fit. Their about 4 or 5 Hemi Bucks a piece, 4 are needed.
I had to do this w/mine.
Get "18mm sparkplug non-fouler" from AutoZone PN 42009, and drill out the bottom of it with a 1/2 bit so the end of the O2 sensor will fit. Their about 4 or 5 Hemi Bucks a piece, 4 are needed.
I had to do this w/mine.
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08-21-2006, 09:57 PM
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#6
08-22-2006, 04:01 PM
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RE: damn check engine lite keeps coming on
This is from another form(<=SP corrected); so I’m just relaying information and staying neutral on the sim thing. Yes... another service manual quote 
I’ve followed another thread on this subject in a GSM form, that thread hasn’t gone anywhere with zero (big goose ege) input from GSM [>:]
I’ve followed another thread on this subject in a GSM form, that thread hasn’t gone anywhere with zero (big goose ege) input from GSM [>:]
I was reading the service manual and I think this explains why O2 sims don't work on our cars.
from the service manual,
Quote:
Monitor Operation - To monitor catalyst efficiency, the PCM expands the rich and lean switch points of the heated oxygen sensor. With extended switch points, the air/fuel mixture runs richer and leaner to overburden the catalytic converter. Once the test is started, the air/fuel mixture runs rich and lean and the O2 switches are counted. A switch is counted when an oxygen sensor signal goes from below the lean threshold to above the rich threshold. The number of Rear O2 sensor switches is divided by the number of Front O2 sensor switches to determine the switching ratio. The test runs for 20 seconds. As catalyst efficiency deteriorated over the life of the vehicle, the switch rate at the downstream sensor approaches that of the upstream sensor. If at any point during the test period the switch ratio reaches a predetermined value, a counter is incremented by one. The monitor is enabled to run another test during that trip. When the test fails three times, the counter increments to three, a malfunction is entered, and a Freeze Frame is stored. When the counter increments to three during the next trip, the code is matured and the MIL is illuminated. If the test passes the first, no further testing is conducted during that trip.
The MIL is extinguished after three consecutive good trips. The good trip criteria for the catalyst monitor is more stringent than the failure criteria. In order to pass the test and increment one good trip, the downstream sensor switch rate must be less than 80% of the upstream rate (60% for manual transmissions). The failure percentages are 90% and 70% respectively.
from the service manual,
Quote:
Monitor Operation - To monitor catalyst efficiency, the PCM expands the rich and lean switch points of the heated oxygen sensor. With extended switch points, the air/fuel mixture runs richer and leaner to overburden the catalytic converter. Once the test is started, the air/fuel mixture runs rich and lean and the O2 switches are counted. A switch is counted when an oxygen sensor signal goes from below the lean threshold to above the rich threshold. The number of Rear O2 sensor switches is divided by the number of Front O2 sensor switches to determine the switching ratio. The test runs for 20 seconds. As catalyst efficiency deteriorated over the life of the vehicle, the switch rate at the downstream sensor approaches that of the upstream sensor. If at any point during the test period the switch ratio reaches a predetermined value, a counter is incremented by one. The monitor is enabled to run another test during that trip. When the test fails three times, the counter increments to three, a malfunction is entered, and a Freeze Frame is stored. When the counter increments to three during the next trip, the code is matured and the MIL is illuminated. If the test passes the first, no further testing is conducted during that trip.
The MIL is extinguished after three consecutive good trips. The good trip criteria for the catalyst monitor is more stringent than the failure criteria. In order to pass the test and increment one good trip, the downstream sensor switch rate must be less than 80% of the upstream rate (60% for manual transmissions). The failure percentages are 90% and 70% respectively.
#7
08-22-2006, 04:35 PM
RE: damn check engine lite keeps coming on
aah yes engine light , i said i another post that this would happin.
i talked to a guy that has a set of headers from i think dynatech ,i think i spelled it right. any way he say's that the high flow cats sit back farther than the stock one's and they don't heat up like the stock one's witch causes a engine light to come on. it's no big deal he say's just have to deal with it.
that why i bought mopar long tube headers these come with high flow cats .and i must say if it comes from mopar then they should work ,after all mopar makes the charger.
i have mopar long tube headers for a week or so anh have had any problems.
if it a mopar then you should probally get mopar parts.
i love my headers there awsome and you really notice the differance.
hope this helps.
go mango 1342
mopar cai
mopar headers
rear defuser
corsa exhaust
73 charger se 440
i talked to a guy that has a set of headers from i think dynatech ,i think i spelled it right. any way he say's that the high flow cats sit back farther than the stock one's and they don't heat up like the stock one's witch causes a engine light to come on. it's no big deal he say's just have to deal with it.
that why i bought mopar long tube headers these come with high flow cats .and i must say if it comes from mopar then they should work ,after all mopar makes the charger.
i have mopar long tube headers for a week or so anh have had any problems.
if it a mopar then you should probally get mopar parts.
i love my headers there awsome and you really notice the differance.
hope this helps.
go mango 1342
mopar cai
mopar headers
rear defuser
corsa exhaust
73 charger se 440
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#8
08-22-2006, 04:49 PM
RE: damn check engine lite keeps coming on
top bannana3767 go back to jba headers post and see what i said would happin.
some people just need to find out themselves.
sorry this happined. the guy i talked to had them and got rid of them.
go out and buy some mopar headers with high flow cats ,and sell them on ebay , some fool will buy them and he will go through the same thing.
if it a mopar and mopar makes the part it should work. after all who knows your car better than mopar?
go mango 1342
mopar cai
mopar headers
rear defuser
corsa exhaust
73 charger se 440
some people just need to find out themselves.
sorry this happined. the guy i talked to had them and got rid of them.
go out and buy some mopar headers with high flow cats ,and sell them on ebay , some fool will buy them and he will go through the same thing.
if it a mopar and mopar makes the part it should work. after all who knows your car better than mopar?
go mango 1342
mopar cai
mopar headers
rear defuser
corsa exhaust
73 charger se 440
#9
08-22-2006, 05:03 PM
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RE: damn check engine lite keeps coming on
Too cool, I didn't know that the Mopar headers came w/CATs.
Just my two centavos... I don't think there is anything wrong non-mopar headers like JBA, Dynatech or Gibson. Some people have had no problems with both that you mentioned, on the flip side some have had CELs (like myself w/Dynatech) but there are ways to deal with it other than staring at the CEL all the time or putting em-up on ebay.
Just my two centavos... I don't think there is anything wrong non-mopar headers like JBA, Dynatech or Gibson. Some people have had no problems with both that you mentioned, on the flip side some have had CELs (like myself w/Dynatech) but there are ways to deal with it other than staring at the CEL all the time or putting em-up on ebay.
#10
08-22-2006, 05:11 PM