M16A swap - feels more powerfull but still sturgling on the highway

Hi guys,
Been reading here for a bit - now it's my time to ask the annoying questions:
My 2007vvt (automatic) started to overheat (probably a siezed thermostat) and also, it started to feel extremely weak.
So, to kill 3 birds in one stone - i decided to swap an m16a into it, sourced it from overseas (probably eastern eu/turkey), put it in, car runs fine, feels stronger down low (not by that much though). overheating problems disapeared as i also put a 72deg thermostat in it (barely passes 85C now)
thing is - on the highways, it still struggles to go over 110(kph).

i used the m16a injectors. and the car has a 2" lift by oldman, 215 bf km3 tires and a roof rack:
Currently i suspect a clogged exhaust of something of the sorts.
Any ideas?

 

The front or manifold CAT are known to disintegrate and block the main CAT, that would limit power at higher revs.

The other thing to check is the air intake and filter, again limited airflow will limit power at higher revs and finally fuel flow or pressure, but you should then see it running lean if it was fuel flow.

Robin

What colour is your transmission oil? The auto boxes are barely strong enough to handle the 1.3. I resisted putting a bigger engine in mine because I didn't want to cook it.
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How would you diagnose this? Get a manifold from a different car? "Sports Cat"? Just driving without the manifold would probably be useless since no back pressure is also not that good, right?

Regarding the color of the oil, i added a pretty big oil cooler, the temp of gearbox oil goes up to about 99C when i hammer it up the mountain to my house(10km of mountain road). I also replaced about 1 l of it.
Got a new strainer filter thing coming in the mail in a few weeks and a new tranny pan gasket, gonna replace both and put fresh oil in it.

If the front CAT has disintegrated it goes to dust and collects on the engine side of the second CAT, which it then blocks. I have never done it myself, but I understand if you take the second CAT off you can see the dust in there.

I have seen someone who slackened the bolts at the joint after the first CAT as a test, but I am not sure I would recommend it, it would be very loud and as you say the wrong back-pressure.

Hi!
By dismantling the downpipe below the manifold you can easily see up into the underside of the cat inside the manifold. flashlight or even better a endoscope, dentists mirror would help.

Or taking down the cat no 2 and shaking it to see what comes out.
(no hard knocks as it could break the element)
However when it is constricted the temperature rises and the dust often burn stuck to the second cat.
It should be open enough to shine a light thru the cat element.

There is nothing sensible to be done to clean it, does not help at all. Just replace.


On my Swift the cat had melted and broken into pieces so very easy to see when dismantled. On the jimny the cat was rattling from all the broken pieces inside and the pieces where easy to see when opened.

My car pass the MOT (Norway) now with removed cat no 1 and a cheap generic aftermarket cat no 2. No idea if I am just lucky though.

From my understanding a free flow exhaust will unleash many gains from the m16a, so i might start thinking in this direction. Meanwhile im dealing with a small leak from the fuel rail, because someone didnt think to buy new injector seals and o rings.

Parts needed 
 
Ignore the fact they are for motorcycle 
These are correct seals

Jack