2 Cats
2 cats?
Thread Starter
|
Senior User
Joined: Mar 2004
Posts: 271
Likes: 0
2 cats?
I was looking at my exhaust and it looks like I have 2 catalitic converters... one before the o2 sensor and one after. Do I need both of these? Can I get rid of the one after the 02 sensor and replace the one in front of the o2 sensor with a high flow one?
Freshman User
Joined: Mar 2004
Posts: 45
Likes: 0
What year is your truck?
It is likely that indeed you have 2 cats. I have a 96, 300 L6 which I just had a custom exhaust built for. I had a bad front cat (yes, it had 2) and was giving me CEL that was caused by cat efficiency code (P0420). I replaced the front cat with a high-flo cat and then 2.5 inch pipe back to the muffler and out behind the rear wheel. Truck runs better now with better gas milage to boot - and no more CEL.
It is likely that indeed you have 2 cats. I have a 96, 300 L6 which I just had a custom exhaust built for. I had a bad front cat (yes, it had 2) and was giving me CEL that was caused by cat efficiency code (P0420). I replaced the front cat with a high-flo cat and then 2.5 inch pipe back to the muffler and out behind the rear wheel. Truck runs better now with better gas milage to boot - and no more CEL.
Postmaster
Joined: Jun 2004
Posts: 2,665
Likes: 0
From: B/CS, Texas!!
One before the O2 Sensor? On my 93, the thing between the cats is the Air Injection Tube. The O2 sensor is before the first cat on a small crossover pipe.
I also removed my second cat....and left it that way
. It's Loud, Hi-Flowing, and Free 
. A Hi-Flo cat will work there.
I also removed my second cat....and left it that way
. It's Loud, Hi-Flowing, and Free . A Hi-Flo cat will work there.
Trending Topics
Thread Starter
|
Senior User
Joined: Mar 2004
Posts: 271
Likes: 0
Will it hurt my gas mileage if I do this? Heres kinda a picture if u dont understand what I wanted to do....
ENGINE========High Flow cat==== o2 sensor ==== no cat ==== muffler === exhaust
ENGINE========High Flow cat==== o2 sensor ==== no cat ==== muffler === exhaust
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Thread
Thread Starter
Forum
Replies
Last Post
loseboltssinkships
1987 - 1996 F150 & Larger F-Series Trucks
15
Jun 29, 2025 11:18 AM
