Hi, I've got a evo 5 with basic mods like exhaust and intake, aftermarket td05 16g, after I change my engine oil, I found that the throttle response sometimes is very slow, but sometimes it response fast. Is this because of the engine oil or something else? What can I do to improve the response?

 

Ported throttle body should help out with the response.

 

Tune

 

log it, see what's going on. could be knock or a loose wastegate. doubt very much it has anything to do with your oil.

 

I'm planning to go reflash my standard ecu, will this help?

 

There may be something mechanical going on.

Did you adjust your throttle cable or mess with anything else? I know when I do my oil change I usually do a boost leak test, check all the clamps, hoses, etc. Maybe you bumped something loose. I don't think changing the oil will change your throttle response unless you put wheel bearing grease in the engine.

It could be in the tune, but if it was great before the oil change and now it's different, then it must be something mechanical. Did you disconnect your battery by chance when changing the oil?

 

No... Does lager throttle body help? Is it has to change with injectors as well? Sometimes in a cold night, it response better.

 

Cooler/denser air at night time with make any car, especially turbo'd ones, run better.

 

You dont need injectors with a throttle body unless evo 5's have tiny stock ones... The oem 550s we got are fine... Sorry a lil foggy on what you get. But yes the ported or new larger throttle body will help quiet a bit... Also a "induction cleaning" might help remove any build up that could be causing a restriction in your manifold... Vacuum leaks from old cracked rubber lines or a boost leak could as well... Have a shop smoke it and clean the intake

 

This is a distinct indication that its in the tune.. cooler denser air makes your car run a little leaner-- hotter thinner air, runs a bit richer-- try the tune FIRST before jumping to other conclusions.

 

which oil were you using before you started experiencing poor throttle response? 5W? 10?

 

take off your right shoe!

 

1) Place foot over right pedal
2) Mash vigorously

 

If lag is the issue during any temperature try adjusting the throttle cable like previously mentioned.

If it feels more responsive at night its the cooler/more dense air.

I've had the same issue; I got my tune in the winter and with it being summertime, I just need a tune.

If you try porting the throttle body without a tune you're gonna run into some A/F issues.
Happened to a buddy of mine, he had rough idle and a crappy ride.

Let us know if any of that helps resolve the issue.

 

Thanks mate, I'll go for a tune.. and I have other question to ask, do you know what size is the evo 5 engine oil drain screw size and sump plug washer size? I'm planning to change oil this weekend.