I have a 1991 LS 400 with a 160k miles on it. The engine and transmission are in excellent condition. The car's engine has been heavly serviced: timing belt, gaskets, injectors seals, starter, alternater, water pump, kyb suspension, egr valve, and all the vaccuum lines have been replaced. I dropped some 18s on the car but I was looking for some more power of this beauty

I been looking on eBay for some performance chips, and there a number that connect to the ECU that control the fuel an oxygen mix and whatnot. Is this a scam or is this pure power without damaing the engine or something else.. Lexus' can be tricky cars.

any ideas for power w/o spening too much