Past owner of both a MY 2000 and 2005 LC. May have an opportunity to pick up a clean 2006 with 150k for mid 20s maybe 26k. Should I be worried about the SAIS enough to limit my search for another 2005?? Also on fence about the AHC. Seems like both of those could cause headaches from all my research. At a minimum I would have to do the SAIS bypass and maybe rip out the AHC if it fails. Truck is extremely clean, no rust. One of the nicer ones I have seen which makes me want to get it but I don't want to get into a lack of reliability. I don’t care about the extra hp around town or the advantage of AHC. Won’t be used as a daily. Only used weekend cruiser. Looking for opinions. Thanks in advance
Wrong thinking!
Unfortunately misunderstanding of SAI & AHC, has lead to many urban myths.
AHC:
AHC, properly maintained, is so sweet. Once you have one, you'll not go back. I've 4 now: 1-03LX, 1-06LX and 2-07LX ranging from 145K to 320K miles.
S.A.I. system in the 4.7L 2UZ-fe VVti:
It is the SAI's internal non replaceable filter, that fails. Which is resulting in issue. SAI filter can be
modified, with easily replaceable air filter. I'm doing one today.
Blocking-off S.A.I, system. IS NOT a street legal option nor needed. They also lead to engine issues, and increased pollution. If caught with one on public roads, streets or HWY is a $20K federal fine. Any shop installing one is subject to fines and worst.
Starter jobs isn't really harder with SAI. It just requires pulling SAI pump and SW, that blocks in starter. It's No big deal. In fact, I typically do starter and SAI mod at same time. Just depends on which fails first, as to why i'm in there. ie SAI filter, starter or rodent chew of wires under intake.
VVti in the 06-07 USA 4.7L 2UZ-fe VVti
In the rocky mtns, we have reduced HP in all internal combustion engines. This is do to high altitude (reduce air density). Climbing high altitude passes, is a breeze, with the added HP of the VVT (06-07).