When the catalyic converter is taking out of the car to reduce back pressure and increase performance. It is illegal though, only if u get caught. it would be hard and almost impossilbe to pass smog check also
Dam ur car stinks, is it running a straight pipe?

Im running a 3 inch down straight pipe wiht a racing cat back system yo. word
by Thomas Van February 25, 2005
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1 (noun, automotive): An exhaust system mod in which all mufflers and catalytic converters are removed, literally having a "straight pipe" as your exhaust. Doing this will increase noise and free up HP. It is very illegal almost everywhere except in M town

2 (verb, informal, sex): {aggressive, rough, hard sex, usually used to describe rough oral sex, face fucking
1: God damn it I'm sick of hearing my neighbors straight piped Honda everyday at 3 AM
2: He Striaght piped me and now my neck is sore
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Straight piping is an aggressive form of deep throat oral sex. This is when a girl lays on her back on a bed (or some other object) and tilts her head back over the edge so her throat is no longer at an angle. In effect, it forms a "straight pipe." Often seen in pornography.

Yo man I banged this girl last night, she was like a pornstar dude! She even let me straight pipe her!
by Dick M. Down March 17, 2008
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When two straight guys "accidentally " have sex while working on their lifted truck
Josh and I spent all night in the garage straight piping, and then we did some exhaust work on my truck.
by Buttstuffisfun November 21, 2016
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To fuck a girl in the ass so hard that she uncontrollably mubble like a 440 motor.
Man last night I heard Haylee was Straight Piped by Conner it was crazy.
by Kren Markland July 19, 2021
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Farting with no underwear on. Nothing to filter the fart.
My uncle was straight piping it at Walmart and left a stain in his jeans.
by Gar Grim March 16, 2023
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When you fart with no underwear on. nothing to muffle the sound.
One night me and my girlfriend were doing 69,and with no warning, the loudest straight pipe I ever heard.
by Pete the Plummer February 8, 2004
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