I'm not the original owner and I don't know what previous engine work was done but i've replaced the thermostat, timing belt, all other belts, water pump, filters, fuell pressure regulator, one injector just for fun, new radiator, engine temp sensor, starter, 90 amp alternator, probably some other stuff too but its never let me down. Had some starting problems but that was fixed with the new starter. I also attached a 4 guage ground from the block to the firewall recently and that helped with a lot of the power loss. Have been thinking about getting rid of it and getting a jeep or sammi but I just can't imagine letting all that hard work go to waste, so I'll be doing the 2wd hardbody steering upgrade or grassroots to give it some more strength.