high flow cat?
#1
#3
#12
The cat dosent read anything. The oxygen sensors do the 'reading'. The ECU looks at the signal coming from the AFR signal in front of the converter and compares it to the signal from behind the converter. The AFR for the rearward sensor should be a higher value due to the fact the catalyst is there. If you want to remove your converter you will be reducing back pressure and losing less torque during the exhaust stroke. To fool the rear sensor into thinking you have a cat simply use 2 spark plug defoulers in series and screw the sensor into those. This will prevent your ECU from detecting the cat is missing and you will not throw a code. The big benefit from this mod is not back pressure, it is that you can safely advance your timing more than if you had a cat and also run a leaner mixture without worrying about knock.. To take advantage of this you must retune your ECU, no if ands or butts.
#14
#15
#16
The whole idea of going to OBD2 in 1996 was to make emissions testing easier. I had my truck tested a few months ago, the test was 100% computer and took less time than the drive in at mcdonalds.
My car also passes, and no - I don't have a cat. No codes = pass.
#18
I don't even think anyone makes a bolt-on midpipe for the ranger. Most sportscars have them available for "offroad" use only on various websites. You'd have to put something together yourself. Seems like alot of work for someone who's just doing it for sound.
Remember that converters are only useful when the AFR is somewhat close to stoich. When you floor it in your truck the engine is heavily loaded and the ECU goes to a much richer tune. In this stage, your cat is basically doing nothing. This is why sometimes I use a tailpipe sniffer when I tune a car that still has a converter - all the adjustments are made to the WOT map, not the cruising map. (openloop vs closed) - The point of this is that you will get some "smoking" when you floor it because its richer on purpose. The ECU isn't even considering this operation because the oxygen sensors arent even being paid attention too, it only uses the sensors on the front side of the system.
#19
Thread
Thread Starter
Forum
Replies
Last Post