Ok, so heres on for you guys! My exhaust stinks like frigin eggs! Ive checked everything. Cleaned maf, throttle body, new ignition coils, plugs, air filter ,fuel filter. All injectors seem to be fine. I have to Check engine lights. My mileage is horrible, so Im thinking that it may be running too rich and thats the fuel that i smell going out the tail pipe, which would also explain the mileage. Any ideas?

 

Do you still have catalytic converters on the truck?

 

Yeah. Ive read to check for a clogged cat, but was also told that if that was the case then most likely an o2 sensor would go bad and case a check engine light. Sound right?

 

BTW-2001 f350 v10

 

What kind of oil are you running? One of my friends ran a walmart oil in his truck and it smelt like a compost heap

 

If you are getting a sulfur smell from your exhaust it is definitely the converters. A converter can "smell" and not be clogged or cause the catalyst monitor to fail.

 

I've heard that if it smells like sulfur, you're too easy on it and need to make some high speed passes on the freeway to clear it out. That's from a Joe Shmoe mechanic, so take it with a grain of salt.

 

Replace or get rid of your cats.

 

A Ford mechanic told me once that a sulphur smell in your exhaust means you have contaminated cats and need new ones.

 

The sulfur smell can come from junk gas too (cheap quality). You can try swithcing to a known high quality fuel plus the long freeway runs could help too. That will let the cats get good and hot.

If it's rich I would think it should smell more like unburnt fuel.

 

Had the same condition with my old S-10. Sulfer/rotten egg smell, bad gas mileage, NO code.
Turned out it was my o2 sensor causing it to run lean (I think lean). It was out of range, but not bad enough to throw a code.(mechanic checked it manually). Swapped in a new one and my mileage shot up considerably.Smell went away and ran much better.

 

Yeah, most people don't bother with O2 sensors... they just keep them in until a CEL comes up. Which is not good. O2 sensors last from 30k to 200k before a code. However I recommend changing them at around 50k to 80k. They are consumable items, meaning they don't last forever. Especially with how the truck is driven.

 

Wow, good info! Thanks. Im def gonna change the 02 sensors, though i think they are a pain in the *** to get to. And def the cat too. Can I just cut out the old one and use clamps to install the new? Or should I just take it to a muffler shop and have them weld it? Any cats that are better than another?

 

Also, do i need to replace the upstream and downstream o2 sensors? Thanks again for all your help!

 

Yes, if it is a cali emissions truck.

I've always frowned on cali emissions trucks in other states... it costs more to maintain them. But most nowadays don't look at that kinda stuff.

There should be a law against it though or a way to get out of it when purchasing a vehicle to un-cali it. As I'd rather have only 2 o2 sensors rather than 4 o2 sensors.