kwb

Short of it first, Saturday I'm going to do a shop-day, what should I look for/address to get my car back in peak performance??

Widget is getting a little old, but I was hoping to keep things running better then they are. We bought Widget new in '07, she was a canceled order for someone else so NO WAIT LIST!! Base model, auto-transmission, now with a little over 173,000 miles. I've done the maint. myself through the years.

About a year ago, our fuel economy dropped sharply, 35-37 down to 25-29 there is also less power then before(which is a big deal when there isn't much to start with, hahaha).
here is what I've done:

• New Plugs, ~140k miles maybe, missed the code
• Checked the valves. They didn't feel like they needed much adjusting, one was a little looser, but I'm not sure it really needed doing.
• During valves, I may have dropped a spacer for the fuel rail in the intake... I did drop it, we couldn't find it anywhere...so I dono. It's currently spaced with a nut and some washers.
• Break overhaul (front only), the calipers stuck for a while and burned through some pads, so I rebuilt them and replaced the rotors and pads. Also did an alignment.
• Transmission drains/refills have been done on time and the valves forced a radiator drain/fill (that block plug is a @#$% to get out!)
• PCV valve is clicking when the hose is pinched, so it seems ok.
• ran fuel cleaner through the system
• sprayed a bunch of cleaner into the air intake... it didn't like that.

The plastic-crap underneath also got ripped off by a curb. I have a new shield, but it's for the whole wheel-well to wheel well part. I still need the little piece that connects the bumper to the main piece. I suspect that isn't helping, but I'm thinking it's only responsible for a few points, not the full 10mpg drop. Plus, the car just doesn't feel right... it seems rough.

Saturday's plan:

1. Recheck valves (something is chattery in there)
2. I have a scope, so I'll see if that piece is blocking air-flow
3. Replace the under-plastic stuff

Is there anything else I can check for?? I thought about doing a compression check, since it feels like it's missing some power.

THANKS!!! We just cleared the loan, I want to keep her for a while.

claymore

How about your air filter you haven't mentioned that. Valves need to be done. You can't feel them because the clearance closes on the exhaust valves so there is no play and no clicking.

ss_zoidberg

Compression check and check your valves. Driving habits/routes change?

kwb

I thought I had some mis-firing before I did the plugs and someone mentioned the Coil packs. Changing the plugs seemed to resolve that issue, is there a way to test the packs?? they are fairly expensive.

I have done the filters along the way. Our driving habit is still what it always has been, although we are in Southern California now, and not coastal Virginia. With that, the fuel economy is about what we had back east. So I don't think the terrain is influencing it too much.

I'll do the valves again and pay closer attention to the exhaust valves this time. If I remember, the specs is sitting between the two feeler gauges I had, so I did my best, but should I air on the side of too tight, or too loose?

claymore

On the exhaust set them to the largest clearance as they close up from use. On the intake just the opposite set to the tighter side as their clearances open with use.

smithenhiven

My 08 base Fit 5-speed had a bad upper oxygen sensor. I was getting consistent 40mpg, then all of a sudden it got progressively worse, down to around 25mpg for a few tanks. I didn't know what was wrong, but the check engine light finally came on which was the oxygen sensor code. I replaced it, and the car is back up to around 35 mpg now. Still not as good as it's prime, but a lot better than 25. I've since had it back to the dealer trying to get that 5 mpg back but they say it checks out, so I don't know.

Maybe your O2 sensor is bad or going bad but the CEL didn't come on yet?

MTLian

I'm getting a steady 19MPG with no engine codes. Called the dealer they said call Honda, called honda they say call the dealer. I had the car inspected last summer and it came back with a clean bill of health so the dealer says everything is fine and nothing they can do. Frikkin 19mpg!