Test Pipe - Running rich ?
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From: Greenville, SC
Test Pipe - Running rich ?
OK, at 100,000 miles I got a CEL saying my cat was not at 100%. Instead of putting on a new cat, I went with a test pipe and non-fouler for the o2 sensor on the cat. ( I have a 2001)
I ran to Fla this past weekend and stayed right at 70 mph the entire 650 miles each way. After I got back to SC (1500 miles later) I noticed a lot of soot on the outside of my chrome tips. It wiped right off with mineral spirits.
My question - will removing the cat cause this engine to run richer ? Hitting Vtec a few times I saw a puff of black smoke, which usually means running rich. At 70 mph, and the top down, I averaged 32 mpg per tank. Normal, low ?
I ran to Fla this past weekend and stayed right at 70 mph the entire 650 miles each way. After I got back to SC (1500 miles later) I noticed a lot of soot on the outside of my chrome tips. It wiped right off with mineral spirits.
My question - will removing the cat cause this engine to run richer ? Hitting Vtec a few times I saw a puff of black smoke, which usually means running rich. At 70 mph, and the top down, I averaged 32 mpg per tank. Normal, low ?
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From: Dallas, TX
00-01 runs very rich and 02-03 have a diff tune to run leaner and have more tq to their tune low end. It's normal for you to see tips real black because your cat filters most of it out and if you remove cat there is nothing stopping all the crap from coming out. Sooner or later you'll see it on your bumper too.
If you want to roll with at tp, I would suggest that you should buy an 02-03 ECU from a junkyard. It's not going to fix it totally, but there will be a significant difference.
If you want to roll with at tp, I would suggest that you should buy an 02-03 ECU from a junkyard. It's not going to fix it totally, but there will be a significant difference.
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[QUOTE=ifly1956,Sep 16 2010, 01:09 PM] My question - will removing the cat cause this engine to run richer ? Hitting Vtec a few times I saw a puff of black smoke, which usually means running rich.
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From: Clatskanie, OR
Originally Posted by deibit,Sep 16 2010, 09:33 AM
And by the way.. removing the cat ill never add more fuel or reduce the airflow.. (on the contrary)
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Originally Posted by deibit,Sep 16 2010, 09:33 AM
that's not always true.. in fact in most of the cases it's the other way round.
Running leaner and/or with advanced ignition (on tuned engines), means that the air/fuel mix is more difficult to burn, and therefore can cause incomplete combustion (in the combustion chamber) and could lead to a postcombustion (in the exhaust manifold or in the cat) or even cause smelly black gas balls coming out of the exhaust (specially if u have a test pipe)
In fact running leaner is what causes tuned cars to popoporropo on reductions like harleys (or even to backfire throwing flames in extreme cases).
And by the way.. removing the cat ill never add more fuel or reduce the airflow.. (on the contrary)
Running leaner and/or with advanced ignition (on tuned engines), means that the air/fuel mix is more difficult to burn, and therefore can cause incomplete combustion (in the combustion chamber) and could lead to a postcombustion (in the exhaust manifold or in the cat) or even cause smelly black gas balls coming out of the exhaust (specially if u have a test pipe)
In fact running leaner is what causes tuned cars to popoporropo on reductions like harleys (or even to backfire throwing flames in extreme cases).
And by the way.. removing the cat ill never add more fuel or reduce the airflow.. (on the contrary)
i can attest to very lean sounding like a subaru
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