check engine light

rokntoy

rokntoy

FUCKIN SLAYER!!!
Joined
Sep 2, 2006
Location
Elkin, N.C.
I have a 96 tahoe and the CEL keeps going on and off. The code says its a o2 sensor and that its running rich on the right side same as o2 sensor side it has a bad hesitation on take off just like its loading up and smells like rotten eggs. Ive already replaced the cat converters on it. I also have been told it could be Im running a KandN air filter. Any ideas?:confused:
 
vortec? 5.7L? check your fuel pressure regulator, its probably leaking! (done been down that road with a 1500. leaks out the "vacuum port" which is just open to the intake, flooding #6 cyl with fuel.. PITA to replace, about 2 hrs job.. requires pulling the top half of the plastic thing that covers the spider. fun to remove and reinstall.
 
Running rich on bank 2 the most common cause is the FPR is leaking . A vaccume leak will not cause a rich condition. pull the air tube off and look in the intake and see if there is fuel laying in it . I see this a lot in my shop
 
Wwildman said:
Running rich on bank 2 the most common cause is the FPR is leaking . A vaccume leak will not cause a rich condition. pull the air tube off and look in the intake and see if there is fuel laying in it . I see this a lot in my shop
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a vacuum leak won't cause a rich condition, it causes a lean condition, which in turn make the system dump fuel to account for it,which can create a rich code.
 
transman731 said:
a vacuum leak won't cause a rich condition, it causes a lean condition, which in turn make the system dump fuel to account for it,which can create a rich code.
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The only time I have seen a vacuum leak on the vortech engine it has a lean condition but the only way to know is reading the fuel trim and o2 sensors readings
 
Ok ive been told its the fuel pressure reg and Ive also been told its the fuel spider. Don't know what the real name for it is and thats what they call it at o'reillys. Has anyone ever dealt with one of these? whats the real name of it and is it a dealer part?
Heres a pic I found on line.
spider.jpg
 
rokntoy said:
Ok ive been told its the fuel pressure reg and Ive also been told its the fuel spider. Don't know what the real name for it is and thats what they call it at o'reillys. Has anyone ever dealt with one of these? whats the real name of it and is it a dealer part?
Heres a pic I found on line.
spider.jpg
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that's the fuel injector. it is all 8 injectors rolled into one unit. its not cheap.. around $300-$350..

the fuel pressure regulator is hanging on the left side of the unit in the picture. on the vehicle, its on the passenger's side of the unit. if under the FPR is nice and clean, its leaking.
 
To check the fpr, you need to leave the upper intake off and reconnect the fuel feed and return lines. Then turn the key to the on position to energize the fuel pump and build fuel pressure. May have to cycle ignition a couple of times to reach maximum fuel pressure. Once fuel pressure builds if the fpr is bad fuel will leak back through vaccum port hole/nipple on the far right (passengers) side of CFIU. Don't see to many problems with the CFIU it self. Also keep in mind it takes a minimum of 60psi to open the the injector nozzles. So if fuel pressure is less than 60psi you may need a fuel pump and/or filter.
 
Caver Dave said:
Before I spent a nickel on a replacement CPFI "spider" unit, I'd spend the extra for the updated/re-designed MPFI unit. Supposedly "fixed" the crappy poppet issues.
http://shop.advanceautoparts.com/we...-BWD_20960205-P_677_R|GRPFUELAMS_567207627___
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From what Ive been told the updated ones are the only ones you can get now.
THE LINK said:
To check the fpr, you need to leave the upper intake off and reconnect the fuel feed and return lines. Then turn the key to the on position to energize the fuel pump and build fuel pressure. May have to cycle ignition a couple of times to reach maximum fuel pressure. Once fuel pressure builds if the fpr is bad fuel will leak back through vaccum port hole/nipple on the far right (passengers) side of CFIU. Don't see to many problems with the CFIU it self. Also keep in mind it takes a minimum of 60psi to open the the injector nozzles. So if fuel pressure is less than 60psi you may need a fuel pump and/or filter.
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A buddy of mine told me there is no vac line to the fpr and if its leaking there will be a clean spot on the intake under it.
 
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