Honda Mobilio: Check Engine + High Fuel + Bad Exhaust

Hey there! I have some experience working on cars and went through something very similar with my 2016 Honda Jazz. The symptoms you're describing sound exactly like what I dealt with. After taking it to my regular workshop, they diagnosed a faulty electric switching valve, which was causing those exact issues, the check engine light, increased fuel consumption, and that nasty exhaust smell. The fix wasn't too complicated, but it set me back about 140 Euro, they had to replace the valve completely. Since then, the car's been running perfectly, and all those symptoms disappeared. Before I share more specific details that might help, Have you scanned for error codes? Did you notice any stuttering or rough idling? How many miles/kilometers has your Mobilio done? I've also owned a Honda City before, so I'm quite familiar with these models. Let me know those details, and I'll try to help further!

Thanks for sharing your experience! My Mobilio has done 209556 KM and had its last service about 3 months ago. Yeah, I'm actually experiencing that rough idling too, especially when the engine is cold. Haven't scanned for error codes yet, was planning to do that this weekend. Really hoping it's just the valve like in your case and nothing more serious! It's good to know the fix wasn't too complex. Did your Jazz also have that slight hesitation when accelerating? That's another thing I've noticed recently with mine. Would you recommend getting it checked at a Honda dealer, or would any good mechanic be able to handle this?

Hey again! Yeah, my Jazz definitely had that hesitation during acceleration, it was super annoying! And wow, your mileage is pretty close to what mine had when the problem showed up (mine was around 195000 KM). From what you're describing, it sounds exactly like what I dealt with. That cold idle roughness was driving me crazy too! I actually went to my regular mechanic first (not Honda), and he did a great job. These valves aren't really brand-specific rocket science, so any experienced mechanic should be able to handle it. Just make sure they're using quality parts. Quick tip from my experience, when you get the codes scanned this weekend, look out for P0411 or P0410. Those were the codes my Jazz threw up, and they're directly related to that secondary air system issue. One thing though, while you're at it, might want to have them check the air pump too. After my valve was replaced, I noticed the pump was starting to show signs of wear (probably from working overtime due to the bad valve). Didn't need replacing right away, but it's something to keep in mind. Let me know what those codes show up, I'm really curious if it's the same issue I had!

Thanks so much for all this detailed info! You're really helping me feel more confident about getting this fixed. Those specific codes you mentioned (P0411 and P0410) are super helpful to know about, I'll definitely keep an eye out for them during the scan. I think I'll follow your advice and take it to my regular mechanic first. You make a good point about it not being super brand-specific work. Really appreciate the tip about checking the air pump too, wouldn't have thought about that! It makes total sense that one problem could lead to another. I'll update you after the weekend once I get those codes scanned and figure out what's going on. Fingers crossed it's just the valve like in your case! Thanks again for walking me through your experience, it's made me feel a lot better about the whole situation. And at least now I know roughly what kind of repair costs to expect!