88 sc mr2 running rich and any cold air intake ideas?

[mr2kydd1790]

my mr2 seems to be running pretty rich. the only time it runs "stoick"? or lean. is when i am in 5th gear running a little below 55mph. anything more then 55 steady with cruise on is full rich on my a/f gauge. any way to get it to run leaner without tuning and or if it is suppose to run that rich or why it is? also does anyone have ideas on a way to make a cold air intake. right now mine is a little ghetto and think it is counterproductive more then anything.haha.

one more thing. on the sc models does any one know what the stock exhaust manifold configuration is. is it 4-1 or 4-2-1. right now im trying to figure out if mine is aftermarket because i bought it with a 4-2-1 and my 87 had 4-1 but wasnt sure if the n/a and sc manifolds where the same.

any thoughts and answers would help. thanks all

[Papo J]

If you don't have a wide band O2 sensor and display you may just want to ignore what you see on your gauge, i really doubt it's accuracy. The NA and SC manifolds are the same except for the EGR pipe bung and they are all 4-2-1 if you take into account the down pipe.

[donnyavery]

what a/f gauge are you using if its not a wideband its not going to be accredit to tune with and to test you go for a ride shift into 2nd gear and hold at 2000rpm and watch (have the passenger do this or use a video camera for safety) and stomp it to red line watch a/f vs rpm you'll get to see where its really rich or lean then you can tune from here
here are a pic of each left is wadeband(the same one i use) right is a narrowband

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for safety i don't recommend you do this on the street use a dyno or a close strip or latest on the intrastate where theirs more room and travel is higher speed

[mr2kydd1790]

so both manifolds are the same. mine is different then because it doesnt look the same. it goes from the block at 4 then goes into 2 pipes then meets up to 1 where it connects to the exhaust pipe with the cat and muffler. but i still fell like its stock because it still has a heat shield on it.

[mr2tim]

As a Corner Marshall for the SCCA for several decades I have seen numerous fires from mr2 racers who do not run their exhaust cladding (heat shields) or use headers with out wrapping.

Those racers I talked to over the years have confessed they see no seat of the pants difference running headers vs the stock manifolds and downpipe.

Catalytics and mufflers are another story entirely.


I too have observed rich conditions on the street, so much so my passengers have asked what the smell is, while their eyes are watering.