Hi. i have a 1997 f150, 5.4 liter v8. recently i did something of questionable legality and had the catalytic convertors removed. don't worry, in oklahoma we don't have emissions testing or annual inspections, so its not a problem. but it does sound really nice, even through the muffler.

my problem is now the sound of what i think is the engine predetonating, or the timing being slightly off. it sounds like the pinging that most people describe when they install headers.

if it is, please help me out in recommendations or suggestions to fix it.
if i've completely mis-diagnosed the problem, also feel free to let me know.

thanks for the help!

 

Did you move the forward O2 when you deleted the cats? Cat deletion should also be accompanied by proper tuning to adjust for flow/location differences, just like long tubes should be tuned for.
The legality isn't questionable, it's illegal (federal law) but that's another story and I'm not a cop so I don't care.

 

If you didn't remove the o2 sensors then you should either remove them or throw on high flow cats (that's legal =P)

 

I did put simulators on the o2 sesnors, so no check engine light. But I didn't do any tuning. How would I tune for this?