Honda Fit Sport 07 not as peppy as it once was
 

Hey, I’m new to the forums and recently bought a Honda Fit Sport 07 in vivid blue for less than 63k miles! This is my first manual transmission car, and so far the car has been great! It’s quick, peppy and a lot of fun. Although after putting on 2k miles on her I noticed a sudden loss of pep after an oil change, coolant flush and new tires installation. Since then I replaced the spark plugs and air filter, and got some of that peppiness back but lacks the quick throttle response it use to have esp. around 3500-4000 rpms+ The car runs great still and has no other issues but I miss that pep!
The car is completely stock btw

Any ideas? New coil packs?

Oil brand name and oil viscosity? Tire pressure before and after?

When I bought the car at the dealership, it had snow tires which had 32 psi, now I have Riken brand all season 40psi all round’
w/ 195/55/15 being the o.e tire size.
Not sure what oil the tire shop used but I’m taking my fit to the Honda dealership for regular maintenance from now on. If it’s bad oil, should I change it to the recommended oil soon or wait until my next oil change? I also noticed I had a bad batch of fuel from a gas station, so I burnt up the remaining tank and now use quality trusted gas stations such as mobile and shell. I alternate between 87 and 89 and the car feels better, just still not the same :/

Oil - quality full synthetic 5w20 or 5w30 (blends are only a tiny bit cheaper so why bother?) (my personal choice for our Fit is Castrol Edge 5w30, but many are good)
Oil filter - OEM Honda (I use K&N filters, but not worth the expense to most)
Spark plugs - ONLY Denso or NGK iridium (Denso IK22's is my personal choice, but the important part is those two brands and iridium)
Fuel - could be debated till the end of time, but the one thing I think most agree on is to choose a high volume station (we personally stick with shell, mobil, or exxon and 93 octane)

Enjoy the new car! Manual Fit's are fun!

How did you "notice" you had a bad batch of fuel?
And how did this correspond on the timeline with the sudden loss of "pep"?

If you were running some bad fuel, the easy answer is clogged or dirty fuel injectors. And that might not go away by simply using up the tank and then switching to name brand fuel.

Just for kicks, and because it's a cheap attempt, I'd run a treatment of Techron through the system and see if anything improves. It might not, but it's an inexpensive attempt.

You use 93 on your fit?
I’m gonna try it out and report back.

I feel the car is clogged somewhere, but I’m no mechanic and I only know how the car use to drive and how the car drives now. 1st and 2nd gear are good but sometimes struggles esp. on hills and I live in the N.E so it’s a common occurrence.
I’m gasing it and feels like the response is slower and somewhat struggling.
Do any of you downshift to 1st gear when approaching hills? I use my 2nd gear for most of my torque/power bandwidth and hardly use 1st gear other than complete stops and really slow rolling.

I noticed I had a bad batch because my spark plugs were brown tipped, indicating bad fuel, and white or black tips refer to other things. I replaced them w/ iridium ngk’s and changed out a dirty air filter.

If something is clogged or dirty, what part of the car is likely to be affected?

I'll defer to the sticky on the GD page - check the butterfly, make sure it's gunk free, and then valve clearances. There's an excellent how to video https://www.fitfreak.net/forums/1st-...started-5.html about half way down. Most seemed to conquer that checking at the 70k interval is better than the 110k interval as the clearance seem to close quite a bit quicker. If it happens to be the oil thing - I know honda's can be picky on the filter. I used a mobil1 filter on my '02 Civic SI, and did not feel right. Went back to OE and it felt fine again. Something about how they design the OE filter and pressure maintenance.

gl

You might want to check your engine oil level. Overfilling will lead to sluggish engine performance and more oil being sucked into the intake manifold

Fuel Injectors...
 

If the fuel injectors are dirty...that could easily affect the "peppiness" of the vehicle.

I had a friend that drove his vehicle as per normal until one day it died and wouldn't start, and it turned out to be a clogged fuel filter. Of course that was a 1970's El Camino.

I'm far from the best person to ask about DIY automotive maintenance and repair. But I feel pretty safe in recommending running a bottle of Techron, it's relatively cheap. See if you notice any improvement or not.

Is the engine stumbling or does it just seem down on power? When you replaced the plugs, did you check that the gap on them was correct? If you misgapped them or inadvertantly had one that had been dropped (e.g. the electrode is practically touching), that could definitely impact your performance.

For the record, brown on plugs doesn't necessarily mean there's anything wrong with them. As they age, they will develop some color.

UPDATE- I need help!!
I used my car today to run errands, everything was running perfectly fine, no issues and I felt that lost of 'pep' was all in my head, maybe getting used to the car?
All of a sudden, I'm stopped at a red light, and as soon as I go on green, I hear a weird but soft crinkling/popping sound underneath me. I drive a MT, and so my 1st gear was running rough, and so was my 2nd, and 3rd. It didn't feel right, and my car was stuttering/jittering from initial takeoff until I was driving above 40mph in 4th-5th gear. Everything started to smooth out until I had to stop again. My car had immediate loss of acceleration and sounded differently too, like almost a deeper tone in the exhaust. I had to pull up near the closest parking because I knew I couldn't drive like this all the way home. I pulled over, open the hood and noticed my engine fuel cap was missing! It had to blown off w/ built up pressure somewhere I'm guessing? Oil splattered the top of the hood and near parts. I called my insurance and had it towed to my mechanic.

Can anyone help and figure out what just happened?
I did a quick google search and found that I might need to replace a PCV valve?
I don't know... and my car has about 65k original miles on the clutch, my friend suggested that I might need a new flywheel/ new clutch.
Thanks for all the help so far!

When you say “engine fuel cap” do you mean the oil cap? ...or the dipstick?

i think it’s unlikey that enough crankcase pressure built up to blow a threaded oil cap off. It was likely just loose - perhaps from your recent oil change... it sounds like that’s when your problems started. Check everything they touched.

when you had the plugs out - did they all look the same? a tan/brown is normal. it sounds like you’re describing misfiring but im not entirely sure. and did the coils look ok? Do you have a check engine light or maintenance minder on the dash?

maybe look into cleaning the TB and maf/map sensor. i would take it to a reputable mechanic or shop to have it diagnosed asap, before you throw any parts at it. It’s really just a guessing game over the internet.

Don't mean to be unhelpful. But at this point I think you just need a good mechanic.
Over the internet sometimes speculation can reach a point where it just creates more questions than answers. You need answers. So a good mechanic would be my recommendation at this point.
Good Luck.

Missing oil filler cap plus loose spark plug or dying coil. More amateur repairs - more trouble:(

Just taking a stab...I'd say overfilled on oil and spark plug under torqued.

I think I agree....
 

I think I agree, which is why I say the OP needs a GOOD mechanic.

Compared to Fit , my past cars were more forgiving to the [lack of] attention to details