Header Installation

[AndreasP528]

Hello I recently installed the RoadsterSport MAX Power 1.8 Inch NC Stainless Steel Header in my 2008 automatic NC Miata PRHT. I ran into a bunch of issues with leaks but after the fifth time of taking it apart I Finally have no leaks but now i have a weird and annoying problem with power. i feel like it struggles shifting and i cant pass 4th gear. I was on a highway and it maxed out at 80 mph stuck in 4th. please help

[Brian]

Straining to think how the header installation would be related....but if old O2 sensor sensor used and is not working to help ECU adjust fuel trims then car would run too lean and be down on power as a result.

[AndreasP528]

Straining to think how the header installation would be related....but if old O2 sensor sensor used and is not working to help ECU adjust fuel trims then car would run too lean and be down on power as a result.

So, what do think i should do? replace both o2 sensors? i have both original o2 sensors in the header and for some reason i don't have a check engine light.

[Brian]

It should quickly toss a code for lean...if lean. If it does not, then I would do a log to confirm or kill this mere guess. The header change may have nothing to do with what you're feeling. It can be down on power for fouled plug or failing coils and numerous other things. Normally for a car with healthy sensors the ecu does some fuel trims in response to O2 data and the car adds the fuel needed for the extra flow through the motor and the car makes more power. But old O2 sensors sometimes just don't function well enough for this normal process to finish. If you work with a tuner like Mike at XeroLimt Motorsports he can quickly see in the data if sensors working.

O2 extensions used? If so, you could unplug and look in the plug for any pins pushed too deep to connect. But again car should give an engine code if O2 sensor not getting connected, or if engine running lean. Without a code, we are just grasping at straws here.

[RobG719]

Hi,

I have a 2010 NC now with a GWR 1.8" header, helmholtz midpipe and superq. I have run it several hundred miles and verified the torque on the header bolts last weekend (all was good).

Recently going up hill pretty hard on the throttle > 5500 rpm, I got a distinct odor of exhaust. It may have been the local traffic/trucks. I tried to recreate when I was solo and seemed to get faint whiff from time to time under similar conditions but nowhere near as strong.

When I got home, I lifted the hood and smelled around the header with the engine idling. Seemed to be only hot metal smell and didn't notice anything under the car. I didn't hear anything unusual either.

Is there a good way to verify whether there is/isn't a leak other than my unreliable nose and ears?

Thanks,
Rob