I did my first oil change yesterday and am really disappointed in the entire splash guard covering over the oil pan. I can't think of one reason why Honda did this on the TSX. I haven't seen this on any Accord or even my old Integra.
To add insult to injury they placed the oil filter directly above the axle and added two slots in the splash guard for it to drain. I spent more time wiping off the oil that was sitting in the guard than the oil change (and I still probably didn't get it all). It doesn't help if you have a leak because you don't know if it is old oil that was trapped or you actually have a leak.

That door you need to remove to get to the drain can't be of any use either.

 

As you found, the TSX is not the most convenient oil change around. The access door does allow you to remove and replace the drain plug (at least that's what I've found), so at least Honda did allow for that. Some here have installed something that makes it more convenient to drain the oil. Something that replaces the drain plug and I assume has like a quarter turn valve to drain the oil (can't be bothered myself, but hey whatever). If necessary, I bite the bullet and remove the right front wheel to access the oil filter (though usually not a problem since I try to time an oil and filter change for when I'm rotating the tires, or putting the snows on, or taking them off...... some time when the front wheel is going to be off anyway). I stuff the area below the filter with rags, then remove the filter. Still a little messy, but way less so than the alternative. Once you do a couple of times, it becomes less of a hassle.

 

Simple....aerodynamics.....and the current '08-up Accords also have a belly pan under the engine/trans (granted with better oil drain/filter access).

 

The "splash guard" is really for aerodynamics...better gas mileage.

I have used a quick change oil valve
http://www.quickoildrainvalve.com/
I have found it works fine...still a bit of spillage when the lever is moved for draining. But you have eliminated worry about stripped oil drain plug threads.

Concerning the oil filter,
I have found if you open the oil drain valve, remove the oil fill cap, and loosen the filter a bit and wait....you will not get much spillage from the filter area...the oil in the filter drains into the oil pan and runs out the drain.

 

I know of at least two other tsx owners (including myself) who have had that splash guard "go missing" after an oil change at the dealership or 3rd party shop. I think the honda techs hate it too I'm pissed because I know exactly which dealership and which oil change this happened at. I'm going to buy a replacement because I don't like things missing from my car, but that's just one more thing to check to see if someone screwed me on the next time I go to get an oil change. But really, it's the biggest incentive for me to start doing these things myself and be done with it!

 

I removed that splash guard a long time ago, and haven't looked back since. Oil changes are pretty easy without it and I didn't notice an MPG hit so it's not a big deal to me. If I could find a nice pretty aliminum one that made things look nicer I may consider getting a replacement, but I doubt I'd ever find something like that.

 

this happened to me also, which i also find irritating. while the piece is relatively insignificant in the grand scheme of things, it is still a part of my car and should be put back.

i actually bought another cover online from a dealership. i don't know what it offers in terms of protection, but i figure if you have the shield on, the likelihood of some debris hitting the oil drain bolt or having salt/sand cause the bolt to seize eventually will lessen.

 

Here in the Northeast, where winter is a very dirty business, I wouldn't consider running without the belly pan. I can't imagine how crappy the front end and engine compartment of my 05 would look after 5 winters (it's bad enough with it in place). I've always assumed it's an aerodynamic aid (and not uncommon; I've owned a number of Audis and BMWs, and they all had something similar, and I know many others use them) and keeping crap out of the area it covers is a bonus. I'm surprised at the reports of dealers taking it off and not replacing it; removing it is not required to do an oil change and/or any of the "inspections" they do.

 

I just completed the first oil change on my car and it was so messy it looked like I had never changed oil before. Draining from the bolt was simple and clean, but taking the filter off seemed an impossible task to do cleanly.

I also found my door cover missing; likely removed by a dealership.

 

The cover is there to reduce the drag coefficient and make it more aerodynamic as well as protect it from the little crap on the road that can/will fly up into your car. Whether it makes a huge difference or not, couldn't tell ya. I don't have it on my car and couldn't really care less tbh. I get fine gas mileage and everything as is.

Changing the oil is an extremely easy process overall if done right. As said earlier: undo the drain bolt, remove the oil cap on top of the engine and then let it drain. After a while I then lightly undo the filter and let it drain some more. After about 5 mins it should be rather clean to remove. Of course some will drip but nothing horrific as I've heard in so many horror stories of changing our oil, a few sheets of paper towel should do the job to clean up the excess spillage in my experiences. The filter location is ridiculous though and hard to get to. I got an oil filter wrench which makes it a whole lot easier to remove the filter, $3 at Advance Auto Parts.

 

I hope you are referring to just the oil drain door and not the entire guard. You want to keep that on to prevent water and other debris from entering the engine bay. My stink with Honda is that it is not needed for the oil pan area.