low99silverado

I removed the Whipple off my 99 5.3l Silverado after 5 years of trouble free abuse. Even with 10 psi with stock injectors I never had a o2 problem. As soon as I removed the SC to sell the truck, I get 4 codes that continually come back
P0137 Low voltage B1S2
P0157 Low voltage B2S2
P1133 Insufficient switching B1S1
P1153 Insufficient Switching B2S1

They come back after 2 drive cycles. While logging The upstreams seam to switch between 400-800mv and cycle normally back and forth. The down streams do the same. It seams hard to believe that all 4 o2 crapped out at the same time. Any common problem known. Possible intermitant wire connection that I cant find. It never seams to trip a code with the scanner attached. Any help greatly appreiciated. In N.Y. we have new emissions inspections, so I have to get it fixed to sell it.

budhayes3

iTrader: (19)

Did the Whipple have it's own PCM programming that has to be reprogammed back?

low99silverado

No, It had the whipple FMU, but no programming to the stock PCM.

budhayes3

iTrader: (19)

The rear O2's shouldn't be switching that rapidly, their main purpose is to monitor the cats. When they do switch rapidly it's usually an indication of cat degredation...hopefully that's not the case.

I'd go back over every connector and vacuum line, make sure nothing's crossed or disconnected. You'd think that something like that would give you other codes (like too rich, too lean, etc.), but you never know. Make sure that the fuel pressure regulator is OK and hooked up so it's not going full rich also. Good luck, hope it's a quick easy fix.

low99silverado

The down streams don't switch as fast I just ment they are not staying at a low voltage like the code says. I have double checked everything i can think of, still no luck. Anyone know if these EGR's are known to stick open? I have taken it off to check for carbon chunks like the 4.3l and it looks good. That is the only thing I can think of that would cause intermitent lean readings, even though they don't set lean codes.

NoChrome

iTrader: (1)

could it be that the computer hasent "learned" less air flow?

budhayes3

iTrader: (19)

Haven't heard of too many EGR problems, but anything's possible. Isn't the EGR an electronic solenoid on our trucks?...also, I think that there's a monitor for EGR flow that should throw a code if there's a problem.

low99silverado

I have put over 2000 miles on it since the removal, I thought it was a fuel trim problem first. I tried clearing the codes as soon as tne light came on and then I drove with it on for 2 months. Once I cleared it, it comes back on after 2-3 trips to work.