So I've doing a lot of research and debating either to even get headers anymore when I looked up obx people complained it cracked and the welding and fitment is off when looked up mvp headers I was aiming for that until I found out people are getting check engine lights but it's like 50% do and don't trying to figure out why would they get cel ? Should I keep stock really don't want to but if I have to how can I avoid getting a cel ? Please help need more hp lol
In Cali you will have trouble with this. Especially if you have a Cali-spec car and not a Federal car. I considered it for an extra 8-10hp and some extra pull up high but the CEL issue might plague you even on an OBD1. There are O2 simulators available but I can't say for certain if this will help with the Cali-spec #3 O2 sensor (which more or less checks "efficiency" and does not report actual varying signals-- as far as I know).
There are a specific set of Bosch (I think) O2 screw-in sensors that are needed for this header.
In general, I don't see the benefit unless this is a 2JZ-GE swapped into a lightweight chassis like a 240SX set up for weekend track use. It's such a minor difference in power and a shift in the torque delivery from the low end to the higher rev range-- which makes more sense in a car that weighs under 3000lbs. On the street the SC300 needs all the low down torque it can get. I'd pair this with a 4.27 ratio if you aren't running one already.
MVP's headers, however, are supposed to be the good ones to buy if you so choose to.
I have a set of MVP headers on my car and have been running it for 3 years now without a cel, although I did have to buy some universal screw in type O2 sensors and splice them to the stock connectors. The only reason I got it in the first place was because my stock header had cracked. The MVP header did help a bit on the top end but like KhanBB6 said the car is too heavy to really feel any substantial gain. As for the cel problem this is actually the first time I've heard about it, maybe some people are using the wrong O2 sensors or did not splice the wires correctly?? I'm not really sure.
Yeah, it increases rasp a lot. How badly depends on the exhaust you're running now (stock vs straight pipe, etc). A good setup is the mvp header + Blitz front pipe + Blitz catback. Yeah it's loud enough to get tickets, but you'll sound a LOT like a modded TT supra.
I'll agree with everyone else. The header doesn't really add any power unless you like to drive above 4000rpm a lot. It hurts daily driving, especially if you're auto.