Question about Chevrolet Tahoe

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I own an 03 Chevy Tahoe 5.3 liter ZR1. My engine light keeps coming on and when I hook up my trouble code reader it display's a PO496 which is descibed as being a excessive (intake manifold) vacuum present. I had this issue before so I went ahead and replaced the intake manifold gaskets as a set. Any ideas as to why this problem persists? Does this mean that there is a leak or could somthing be clogged causing the higher vacuum? I do have a degree in diesel mechanics but it's been 20 years since I wrenched on a vehicle of any kind. Please let me know if anybody out there has a quick fix or somthing I could check.

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Check your vacuum hose and your egr valve.

Posted on Mar 29, 2011


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