Expedition rough running exhaust smell

Having a nightmare with my 2003 Ford Expedition, gasoline engine. Check engine light is on, and it's running super rough. Noticed what seems like an exhaust leak and a really strong exhaust smell, almost overpowering. Odometer reads 38441 km. Thinking it might have something to do with the exhaust treatment system, maybe the lambda sensor? Anyone else experienced something similar? Is it possible to fix the malfunction without replacing the whole exhaust pipe?

4 comment(s)

I had almost the exact same thing happen with my Expedition. Check engine light, rough running, and that awful exhaust smell. It could be the lambda sensor, but have you checked the NOx sensors too? Are you using DEF fluid?

Thanks for the quick reply! NOx sensors, huh? I hadn't thought of that. And DEF fluid... honestly, I'm not even sure if my model uses it. Where are the NOx sensors located typically? Is it a DIY job, or should I just bite the bullet and take it to a workshop?

Yeah, definitely check the NOx sensors. My Expedition didn't have DEF fluid, so you're probably good there. As for the sensors, it's probably best to get a diagnostic check and a professional opinion at a workshop to see what's going on.

Appreciate the insight. Took it to the shop as suggested. Turns out it was indeed the lambda sensor causing all the ruckus. Cost me about 375€ to get it sorted, but at least the rough running and the exhaust smell are gone! Thanks again for the help!

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