So basicly I have a 98'xj that is my toy, and a 99' is my DD

My plan is to take the intake manifold out of the 99' and put it into the 98'.

But I still need my 99 to run since its my DD.

MY question is can the 98 intake manifold fit direct bolt on to the 99 without tripping any codes and it not functioniong right?

 

yes it can but whats the purpose of this? unless it's a late 99 the intakes would be the exact same in which case would serve you no benefit

 

I just checked it, and the manifolds are different,, the reason I want to do this is because I heard its a lil gain in HP, since its my project XJ im doing as much work as I can cause im broke at the moment

 

the only way you'll notice the performance gains is if you have other things done like oversize TB, cai, exhaust
I did this with my 96 and it was fairly easy

 

oh yeah,, thats all on my list,, I own a 98 and 99 so im just transfering over all the goodies to the 98'

 

I think it will throw cel cuz late 99+ were diff with emissions.
An the manifold swap is a hit or miss on earlier motors.

 

what do you mean hit or miss? I know in the 2000-2001 models theres more o2 sensors,,, Mine has only two

 

Hit or miss as fars as power adder.
My buddy did it an got nothing even with dui intake headers exhust.

 

His 99 Is about the same as the pre99's...it has the same amount of o2's and still has a dizzy.

However if you have the 0331 head you will probally notice a bigger power Decrease on the DD with the smaller manifold.