I have the L98 in my t/a and its knocking pretty bad after 2500 rpm. Its starting to stall on me too when idling. You can hear the idle go up and down and try to stall and then sometimes actually stall. Every now and then the SES light will come on but it goes away after like 20 seconds of being on. I seriously think I'm getting no more than 75 hp right now cause its extremely, embarrasingly slow. Auto zone told me its possibly my TPS sensor. Any one know what I should do here? Im saving for a new engine but thats not for at least 2 monthes in which this one has to survive. Its also leaking oil pretty bad.. Any help is appreciated. Thanks guys.

 

You should pull the trouble code, check timing, check TPS voltage, and then come post what you find.

 

Ok, I'm getting a code 21 and a 42. The timing was recently set to the factory recommendations under the hood. Thanks!