i noticed i was boosting 16 psi before i got anew cat.(had a cracked flex pipe) once i got a new cat i was back down to at about 13 14.. now i hit 10psi. im trying to write things off of what it could be. belt slippage? leak?.gague messed up? its a 2.9 pulley. any imput on what to check for? i changed my intake to injen from airbox mod and put a flowmaster exhaust on. maybe my intense tune needs to be recalied due to that? any ideas?

 

Belt slip causes overboost so it's not that
when you turn ur car on, does the gauge automatically reset itself to 0? If so, probably not the gauge
Most likely your exhaust...free flowing exhaust will cause you to see less boost...but not that low on a 2.9 I wouldn't think.

Could be a bad bbv that's not closing all the way when its supposed to. If I were you tho, I woud def look into a custom tune from someone actually sittin in ur car

 

actually my gague is at -20 when i start and it idles. maybe my gague is mesed?
up?

its goin to get a custom tune.. once my 2.7 and 60s and heat exchange get here.

 

were you holding a solid 16 before or did it drop off during a pull

 

it would hold a solid 16. how do i check the bbv ?

 

the solenoid?

 

How would belt slip cause an overboost???

 

yea thats what I was gonna say...good god the tech advice I see on this site sometimes sickens me....

That being said.....I would bet it is belt slip. My other car (03 Cobra) loses boost after about 5K on a new belt. You can even see it "gloss" up from slipping. Quick way to check is run your finger right below the blower snout, behind the pulley. If it come back black you have belt slip.

The more free flowing exhaust you have to lower boost you will have also.....to a point. It is usually only 2-3lbs tho. And this is on a V8. Not for sure how much you would lose on a little 2.0. Did it feel liek you lost alot of power right after it was installed too?

 

This isn't always true tho. I am completely straight all the way back from the header to exhaust. can't get much more free flowing than that. And my blower is lightly ported, and i see 17-17.5 on a 2.8

 

compared to completely stock exhaust you will have lower boost with a free flowing exhaust.

 

with the new exhaust on it feels like it goes better. but i remmeber when i first has the 2.9 on there. it friggen ripped. im ganna check the belot out like u said and grab a gm shortned belt, for 45 bux its not ganna hurt to replace it anyways. ill keep you guys posted..

 

go get a Gates, or go to napa and get their house brand belt. Its cheaper and is made by Gates.....