Cat bypass - DME adjustments needed??
01-08-2002, 07:36 AM
#1
Drifting
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Cat bypass - DME adjustments needed??
Bought my C2 tiptronic with Cat already bypassed. Cars runs fantastically, but as its my first & only 964, I've got no reference for comparison.
Does the removal of Cat require any electronic fiddling (lamda sensors etc if there are any.
Cheers
Does the removal of Cat require any electronic fiddling (lamda sensors etc if there are any.
Cheers
01-08-2002, 07:43 AM
#2
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Dear John,
The only adjustment that can be made to the entire system is via the CO2 adj. This should only be ever touched with the correct equipment hooked up. There are no other adjustments you can make. For anything else you need the services of a professional. Playing with the the DME etc DIY, can lead to some horrendous problems. You need a guy like Phil for this type of work.
Ciao,
Adrian
911C4
PS: Cat bypass can certainly mess up your emissions. There have been quite a few 964 owners (not TIPs though) who have installed bypass pipes and failed the more stringent emissions tests. I do not know what is done in the UK though.
The only adjustment that can be made to the entire system is via the CO2 adj. This should only be ever touched with the correct equipment hooked up. There are no other adjustments you can make. For anything else you need the services of a professional. Playing with the the DME etc DIY, can lead to some horrendous problems. You need a guy like Phil for this type of work.
Ciao,
Adrian
911C4
PS: Cat bypass can certainly mess up your emissions. There have been quite a few 964 owners (not TIPs though) who have installed bypass pipes and failed the more stringent emissions tests. I do not know what is done in the UK though.
01-08-2002, 07:50 AM
#3
Drifting
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i don't intend to do any DIY fiddling at all! I was just wondering if I should hae Strasse (independent Porsche specialists in Leeds) check anything.
MOT wise, it DID fail the MOT at Strasse, however I ranf the MOT department and spoke to a chap who explained the whole procedure. Cars after Aug 92 manuf, if fitted with a CAT nee emission testing. The machine at the MOT bay should have a set of standards for a whole bunch of cars. If they don't, they use a standard set. It seems my engine number series (which escapes me for the moment!) doesn't appear on the MOT depts. records, so the standard should apply. It may still fail this, but the solution i to take it where it was MOT'd last time. This MOT station had a brilliant, yetignorant approac " there ain't a CAT on this car mate, so we ain't testing its emmissions!!!" What a win!!
MOT wise, it DID fail the MOT at Strasse, however I ranf the MOT department and spoke to a chap who explained the whole procedure. Cars after Aug 92 manuf, if fitted with a CAT nee emission testing. The machine at the MOT bay should have a set of standards for a whole bunch of cars. If they don't, they use a standard set. It seems my engine number series (which escapes me for the moment!) doesn't appear on the MOT depts. records, so the standard should apply. It may still fail this, but the solution i to take it where it was MOT'd last time. This MOT station had a brilliant, yetignorant approac " there ain't a CAT on this car mate, so we ain't testing its emmissions!!!" What a win!!
01-09-2002, 12:30 AM
#4
Race Car
The only thing I've heard of is when someone has an "open exhaust", meaning less restrictive due to removing one of the primary/secondary mufflers and/or catalytic converter is to get an upgraded chip to reflect the modification...I believe this is to enhance the low end that one may have lost by running a less restrictive exhaust setup.
I only have a primary muffler, the one in the middle, a modified unit by Fabspeed...and am soon to don a "European Bypass" (Cat pipe)...I do have a chip to plug in once I get the exhaust finished up, but am told it's not required for it to run well.
A car will run a bit lean once the exhaust is "opened up", so a chip with fuel re-mapping could only compliment the setup.
I only have a primary muffler, the one in the middle, a modified unit by Fabspeed...and am soon to don a "European Bypass" (Cat pipe)...I do have a chip to plug in once I get the exhaust finished up, but am told it's not required for it to run well.
A car will run a bit lean once the exhaust is "opened up", so a chip with fuel re-mapping could only compliment the setup.