2013 Honda Pilot P0404 error code?

[Dov]

Saturday after 4+ hours of driving gf's Pilot in 90+ heat Check Engine light with check emissions system came on at same time as VTM4 (AWD & traction control) light came on.

No rough idling, misfiring, or anything else odd.

Pulled over to first safe spot turned off car and checked gas cap and looked under hood didn't see anything obvious.

Restarted car and VTM4 light was off but Check engine light stayed on, rest of the day of driving the VTM4 light would come on after ~20 minutes of driving.

When we got back home stopped at O'Reillys (auto parts store) and only trouble code shown is P0404 which is likely EGR related.

Emissions Check engine light stayed on even after the reset at the parts store.

From various sources online it looks like the VTM4 light will come on and system will be disabled if it senses various engine issues.

Also found this TSB https://www.tsbsearch.com/Honda/13-103 via Honda forums but oddly that TSB doesn't show up on NHTSA list for 2013 Pilot or on https://www.autocodes.com/tsb/search...404&make=honda latter shows TSB for Honda Odyssey

I don't consider myself a full mechanic but I was assistant manager at auto parts store when younger, and prior to my pain issues did all regular maintenance on my own cars.

I've got buddy in town that is a mechanic, former Ford Dealership mechanic now senior mechanic at independent shop but its a holiday weekend and I probably won't hear back from him till maybe next weekend. Schedule wise it might take weeks for him to have the time to work on this outside of his day job (ie far less $'s), I know Garage he's working at is running 2-3 weeks out at best for opening to work on anything and any place else I trust around here would be similar.

Additionally this coming week is very busy for both of us since its start of school year and we are working school related jobs.

Few questions I'm trying to get reliable answers to:

I know on older cars EGR/emissions stuff not likely to damage engine or anything if you need couple weeks or more to get it fixed, but I'm seeing conflicting information about this generation of Honda Pilot. Is it okay to drive it loaded full of stuff for few weeks with this issue or not? Girlfriend uses it for her part time Craft business selling crafts at various shows and has big show coming up next weekend that she's already paid for and its a big money maker for her. My car is optimized for MPG not cargo capacity since we have her SUV.

Anyway short of going to dealer to see if this Pilot has received the update mentioned in the TSB?

Not clear to me if the update should be done before or after replacing EGR, the TSB lists it as last step but my understanding of the potential issue is the software can cause damage to the EGR in some situations, and IDK if Covid related price hike but the EGR is $235 (I checked several cheaper online sources the listed about hundred less but they were all out of stock) so don't want to have to put two of them in.

[Welder]

I don't know anything directly about your problem, but a quick google search for "forum 2013 pilot p0404" got me a lot of examples of problems with 2012 models. People were often removing and cleaning their valves with success as opposed to buying new. It sounded like a pretty easy job. I might try that first if you have a few minutes, a few tools, and some cleaner of whatever kind they're using. I'm sure youtube is your friend too.

[Dov]

I don't know anything directly about your problem, but a quick google search for "forum 2013 pilot p0404" got me a lot of examples of problems with 2012 models. People were often removing and cleaning their valves with success as opposed to buying new. It sounded like a pretty easy job. I might try that first if you have a few minutes, a few tools, and some cleaner of whatever kind they're using. I'm sure youtube is your friend too.

With my pain issues I don't turn a wrench anymore, it causes debilitating pain for days or weeks. Can do it if I have to somewhat but there is no point in doing that now because I would end up missing work.

[camel]

You should be ok with this code waiting to get it into a shop. Your gas mileage and function of the vehicle will suffer.

But your risking other things on the emissions system. You can try a cleaner through the emissions system. That can create more problems. If it was me I would drive it.

[Dov]

You should be ok with this code waiting to get it into a shop. Your gas mileage and function of the vehicle will suffer.

But your risking other things on the emissions system. You can try a cleaner through the emissions system. That can create more problems. If it was me I would drive it.

Thanks.

I'm also wondering if this might take some time to troubleshoot, no rough idle which I'd expect if EGR was stuck open. No pinging which I'd suspect if it was stuck close.

Also fuel economy is still normal 20 MPG (calculated by hand and display), we keep mileage logs for all our vehicles I had CDL when I was younger and my dad was over the road semi driver so I have always done that. Nothing weird in last 60 days for fuel consumption.

And we put at least 70-80 miles on it after the idiot light came on.

Unless something comes up I'll run it to closest parts store again Monday and have them run scanner on it and try resetting it again. Engine light didn't go off when we reset it Saturday but engine was still hot.

[camel]

Thanks.

I'm also wondering if this might take some time to troubleshoot, no rough idle which I'd expect if EGR was stuck open. No pinging which I'd suspect if it was stuck close.

Also fuel economy is still normal 20 MPG (calculated by hand and display), we keep mileage logs for all our vehicles I had CDL when I was younger and my dad was over the road semi driver so I have always done that. Nothing weird in last 60 days for fuel consumption.

And we put at least 70-80 miles on it after the idiot light came on.

Unless something comes up I'll run it to closest parts store again Monday and have them run scanner on it and try resetting it again. Engine light didn't go off when we reset it Saturday but engine was still hot.

That year vehicle I believe needs so many key offs and ons on reset. Unless reset by a factory or equivalent tool.
But again. Your okay.

[0ddl0t]

You should be ok with this code waiting to get it into a shop. Your gas mileage and function of the vehicle will suffer.

But your risking other things on the emissions system. You can try a cleaner through the emissions system. That can create more problems. If it was me I would drive it.

I'd be leery of driving it long term unless I knew exactly how Honda was using egr. Back in the day EGR used to be only about reducing NOx emissions, but these days many automakers are using EGR to chemically throttle the engine while keeping the butterfly valve throttle open more. This dramatically reduces pumping losses, but can cause issues when egr gets partially clogged especially passages to one or two cylinders. Those cylinders can run lean even as the oxygen sensor tries to make crude bank-wide adjustments.