I have a 91 4X4 V6 Toyota Pickup. I have a K&N air filter and a magnaflo cat back system. I still have a very hard time towing and traveling in head winds. I was wondering if anyone has upgraded there catalytic converter and if it helped much more than a free flow muffler? Also, I have heard so much good about computer chips, but can we get them for Toyota trucks and 4Runners? Please help me out.