Hello, I posted earlier, but in the wrong sub folder, and I cant move or delete my original post.

I have a 2004 g35 coupe 6mt that I recently purchased. I also have a 2004 G35 coupe that is a 5AT.

The 5AT has much quicker acceleration, and it pulls harder and overall just feels much stronger power wise than the 6MT

The CEL light is not on on the 6mt. It idles smooth, accelerates smooth, I feel no miss or cutting out under acceleration. Its just sluggish compared to the 5AT, and its a very noticeable difference.

The 6mt has 167K miles on it and the 5AT has right at 100k. Neither car has any mods, they are both completely stock.

I need to do a compression test for starters, but besides that, does anyone have any suggestions or insight?

Thanks!

 

What about regular maintenance? Fluids/tires/plugs...

 

Both cars are well maintained. Regular oil changes, engine is very clean. Overall the car is in good shape, it doesn't appear to have been abused in the past. I do plan on changing plugs when doing the compression check.

 

Had the clutch been recently replaced on the 6MT? Maybe it was adjusted wrong and always drags a bit.

 

As far as I know it has the original clutch. The clutch isnt slipping though, there are no jumps in the rpm.

 

the coupe is heavier than the sedan

 

They are both coupes

 

maybe u dont know how to drive a manual well?

 

Yeah....that's not much help...at all

 

Maybe cat is plugged?

 

Now that you mention that I think the exhaust is not quite as loud as the 5at. So that's a good possibility. Maybe it's just my bad hearing...its not what it used to be!

I am changing the plugs when I check compression because I don't know when the previous owner changed them last.

 

It happens more than you'd think. Consider swapping them out anyways when you are down there for HFCs or test pipes .

 

I have been wanting to swap them out anyhow...now I have a pretty good reason to do so!

 

if the cats are plugged, then you need to find out why. in my 2003 6mt coupe the previous owners swapped in longtube headers (no cats) but never did any other maintenance (plugs or anything)


when I got the car and worked thru the maintenance I discovered the fuel injectors were dribbling badly, and all that extra fuel is most likely the reason he had plugged cats and installed longtubes.


so jn other words, before you add new cats..figure out why they may have clogged..or risk wasting that money. of course, test pipes won't be affected.

 

Good idea! ^^^^