BBK Long tube headers and check engine light
#1
BBK Long tube headers and check engine light
Whats up guys, kinda new here, first things first, i just bought my 2003 GT and the guy that had it before me installed the BBK long tube headers and BBK X pipe exhaust with cats. When i got it from him he said that the computer needed to be reprogramed bc of the headers being longer than stock, it throws off the o2 sensor reading. ok makes since. talkd to some guys here in town and national speed said i need to get a programmer, some other guys say i can just get the MIL eliminators. what do i need to do?? any help would be nice. also, does anyone else have problems with the headers hanging down too low?? i feel like mine are lower than they sould be
#2
If it were just the missing cats MIL eliminators would probaly fix things up (you can make your own for $5); however...
The long tube headers relocate the front O² sensors further downstream than the stock position, this requires that values in a table in the tune--the O² Transport Delay table--be made larger. The values represent the amount of time in seconds that the PCM expects a change it makes in the AFR to be reported by the O² sensors, because they are moved further from the engine with the LTs these values need to be increased by 10 to 20%.
Here are the values I usually use, a 12% or so increase. The highlighted values are the new delays, the other the stock values:
The long tube headers relocate the front O² sensors further downstream than the stock position, this requires that values in a table in the tune--the O² Transport Delay table--be made larger. The values represent the amount of time in seconds that the PCM expects a change it makes in the AFR to be reported by the O² sensors, because they are moved further from the engine with the LTs these values need to be increased by 10 to 20%.
Here are the values I usually use, a 12% or so increase. The highlighted values are the new delays, the other the stock values:
#5
Do you not have a tune/tuner now?
The 4-bank chip uses a feature of the PCM called bank-switched memory mapping to tell the PCM to use a particular tune stored in one of five memory banks--the onboard default memory bank or one of the four banks on the daughter-board chip. Because of this the stock tune is always available by just unplugging the "chip" from the PCM.
I use Delta Force Tuning's eight-bank chip and have come to like it now that I have my three "seasonal" tunes nailed down. It is not something I would use for development or tweaking as it has to be removed from the PCM to be programmed.
Delta Force 8-bank chip and burner:
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There is no "going in to the computer" and making changes, the only way (see below) to modify the tune is to download it from the PCM, change it, and flash the new tune back.
A device known as the Moates Quarterhorse will let you tune on the fly, using a laptop PC, as you are diving down the road. It was originally developed for the EEC-IV ("eek-4") system and has limited support for the EEC-V ("eek-5"). I have one I was given for evaluation however I found it to be more of a novelty--it's really neat playing with the tune while (someone else is) driving the car--than anything else. If one had a fire-breathing track burner is would be a different story I'm sure.
Moates Quarterhorse and accessories:
"What's the $5 way" has been covered by Mike T...
#6
yea i havent gotten a tuner yet but im planning on getting one. Just been looking around trying to figure out what what be the best for me. Im not racing it, every once in a while ill get on it on the hightway with others but 95% of the time im just driving it to work and back and around town. Im just wanting to get something thats going to fix the check engine light and make it not run so rich.
#7
yea i havent gotten a tuner yet but im planning on getting one. Just been looking around trying to figure out what what be the best for me. Im not racing it, every once in a while ill get on it on the hightway with others but 95% of the time im just driving it to work and back and around town. Im just wanting to get something thats going to fix the check engine light and make it not run so rich.
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