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Old 10-09-2015, 02:35 PM   #18
ls1nova71
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Join Date: Dec 2009
Location: Independence Mo
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Re: Lean Bank1 and Bank 2

Quote:
Originally Posted by BR3W CITY View Post
Unless its flex fuel, no. Return or returnless, they all ran the 58-62 rail pressure. Only the Flex fuel trucks (metal rail) ran the lower pressure. In 2003 you could get a plastic return rail, a metal flex fuel rail, or if it was a late-production run you could get the returnless plastic rail.
Quote:
Originally Posted by not2oldchevy View Post
The only fpr that will fit a 2003 return system will only do 52 pounds pressure.
Not to play Devil's advocate, but there are a couple different flex fuel rails, but they are not all metal. Some are plastic and look just like the non flex, which is probably what not2oldchevy has. They are distinguishable by where the vacuum port is on them. Flex fuel rails will have the port in the center of the side of the regulator where as the non flex will come out of the top. Here are two pics, the one in my truck is a non flex, the one sitting on the hood is a 2003 flex fuel rail. You cannot switch the regulators from flex to non flex, they are completely different, trust me, I tried!
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