I have a 1999 Silverado with the 5.3L Vortec and 114k miles. It is stock except for a K&N air filter (just cleaned),dual exhaust and 285/75/16 tires. I have been noticing a problem lately that has me concerned. When I start the truck up, I always let it warm up for a minute before driving. Lately when I first take off, if I give any more than very light throttle, it bogs down, hesitates, acts like it can’t get out of it’s own way. Then after 10 seconds or so, it runs normally.
I also notice that sometimes when I am in overdrive and I slow down, then accelerate it doesn’t downshift and gets bogged down at low rpm and studders a bit, which I remedy by pushing the tow/haul button to get it to down shift. My theory is that this is caused by my 285/75/16 tires being larger than stock.
Anyone have any insight? Another thing to consider is that I had the fuel pump replaced about 30k miles ago after it went bad. Not sure if that might have anything to do with the 1st problem
Thanks for any input. I really appreciate it.