Air Intake Systems...

i have the jba's too i think the guy who put them in damaged an o2 sensor, however, he said he ordered a new one and tested it and it still did it. I had them put the stock manifold back on and toyota said it was a bad o2 sensor, they repllaced it (warrantee) and it works fine, The bad thing about the headers is that unless you get rid of the cats and all, the headers add about 5-10 hp.... sounds great though!

 

They might only give 10HP ish but the motor will breath a lot better and should give more low end and better MPG as there is less bottel neck in the header.