Can the trans cause a vacume leak ?

golfballs · February 25, 2007

I know everyone here is going to think im nuts but i cant seem to find out what is wrong with my van. I have a 2000 GMC Savana G2500 5.7 cargo van that has set 0171 and 0174 system to lean codes. I have replaced the secondary ignition system and checked the vacume hoses, the intake and everything else and cant seem to find the cause of the lean condition. Im down to two things that i know are bad but i dont think they have anything ti do with the lean condition. First thing, is there any vacume through the trans that can cause it ? My trans dip stick is missing, i know that sounds crazy but i thought i would ask. Also one of my catalytic converters are empty (hollow), could that cause a lack of back pressure and make it run lean ? I know i sound nuts but i dont know where to go from here to solve this issue. I asked the emisions place about the cat and they said no . Thank you for your time and advice .

Jim

RCH · February 26, 2007

The transmissions use sensors that work with the ECM and are monitored electronically now. I don't think your vacuum is leaking there, but leaving the dipstick tube open is asking for transmission problems (dirt and ...). Have you checked fuel pressure and for a clogged injector, or even a faulty sensor?

wct · February 27, 2007

hey it is possible that you have a faulty O2 sensor or a leak in your air duct air filter area. It is also possible that you have a leaking intake and they are very hard to diag. they have new updated gaskets that are teal green in color ond the original ones are orange. If you O2 sensor readings are ok (if you can read them, not sure how you pulled codes) Then I would recommend replacing intake gaskets and measure for a worped intake-WCT