When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
If it's that bad, I'd check for a CEL as it probably will have one. Pull the code and go from there. What pops into my mind is an extremely clogged Catalytic converter(s). Pull code first...