Exhaust or Tune?

[sneakypete]

I have Texas Speed long tube headers, catless mid pipes that are running through the NPP mufflers. I recently had a generic P0300 code. I replaced all the spark plugs and the O2 sensors. My car’s exhaust fumes are so damn strong that if you stand behind it while it’s running your eyes will burn and your clothes will smell of gas in a matter of seconds. Is this normal for a catless car or does it sound like my car is running too rich?

I don’t have a wideband to check my AFR but will pick one up if it appears to be running rich.

[craigd853]

It's from not running cats. These help absorb that smell. I running hi flow cats on my 2010 with TSP long tubes and as soon as I switched them out i could smell more fumes. Tuner said it was normal and i do have the AFR gauge installed on my car. He was correct, all good. Hope this helps

[eLeSthree]

Originally Posted by sneakypete

I have Texas Speed long tube headers, catless mid pipes that are running through the NPP mufflers. I recently had a generic P0300 code. I replaced all the spark plugs and the O2 sensors. My car’s exhaust fumes are so damn strong that if you stand behind it while it’s running your eyes will burn and your clothes will smell of gas in a matter of seconds. Is this normal for a catless car or does it sound like my car is running too rich?

I don’t have a wideband to check my AFR but will pick one up if it appears to be running rich.

That’s called “Merica! Hells yea!” That’s panty droppin powerfume! Lol, jk man, but yea thats normal. If this were my daily, I’d consider putting in a set of universal 3” high flow cats. Might cost you 1hp, and will help with the stink.

The random misfire code could be from a wire touching a header primary, a bad coil or plug. I got some misfire codes when i installed tsp 2” headers, but they went away when i installed a nice thick set of Taylor sparkplug wires and made sure none were touching a header.

[christianchevell]

You did tune the car with a tune ? Its in the tune if the car is running too rich but yes as others said the cats help cut the gas smell and I believe even help make more decel/fuel cut off popping from their heat and make the car legal most places.......And the tune cannot change the smell if your already tuned well with Stoich and you should have the front o2s operational yet with the code for delayed response blocked and the rears disabled.... in the tune..... and well if you got a remote tune things like a preloaded tune can have unless your just not into say a different fan on off or no 1-4 shift or Hill start assist etc.... it adjusts the AFR with preloaded tables hopefully changing things out to maximize on your mods selected for the "Canned tune".

You must be in CAL where you don't have to smog.....or come from somewhere else licensing it, or are waiting the four years or so ? before they ding you get a new car checked..?

[frankwjr]

you should touch base with dynoSteve at RDP...you really should get a tune, leavin so much on the table without it...my setup is 50 state legal, no cels, 20+ HWY mileage AND I DD the car unless it's raining or snowin....good luck!

[Leo72793]

Originally Posted by sneakypete

I have Texas Speed long tube headers, catless mid pipes that are running through the NPP mufflers. I recently had a generic P0300 code. I replaced all the spark plugs and the O2 sensors. My car’s exhaust fumes are so damn strong that if you stand behind it while it’s running your eyes will burn and your clothes will smell of gas in a matter of seconds. Is this normal for a catless car or does it sound like my car is running too rich?

I don’t have a wideband to check my AFR but will pick one up if it appears to be running rich.

Catless makes it run lean/rich depending on throttle.

Tune can correct it. or high flow cats. it helps reduce the scent alot.

[sneakypete]

Steve did the tune on my car when I changed out the Cam. Ive had catless cars in the past but I don’t remember them being this strong smelling. It may just be the difference in cams.

[Gunmetal Speedster]

I'm cammed, longtubes, no cats and mine isn't as bad as that.. I suppose getting it checked wouldn't hurt

[Avenging Orange]

It's hard to help when you leave out important info....like having a cam.....whether it was tuned (canned or dyno). Those things are kinda important....from someone who says they have had modified cars in the past.
That being said. You will always get some fuel smell, even with hi-flo's. But pungent overwhelming is in the tune. The car should really be properly tuned on a dyno if you have a cam.