Why should I not buy a MK2 GTI with a 1.8T engine swap?

If you don't know the quality of the swap (i.e. what shop did it, etc.), don't do it. A lot of the time swapped VW's will list the shop that did the swap as a pedigree. Overall the 1.8T was a great little engine with awesome tuning potential especially in a very light mk2 body. That being said there are many electrical and sensor issues that can arise from using a 1.8T from a mk4. UNLESS you yourself intend to re-do the swap or are experienced with hand's on engine swaps and wiring/ECU tuning.

What about vehicle annual inspections in your state? Non original engine could be a headache.

My 85 GTI 1.8 was the best car I ever owned it's a breeze to work on it's fun to drive it only had two owners and was extremely well maintained and it drove like it was brand new even though it had 260,000 miles on it. I was beating brand new vtecs (stock of course) and some vr6s too but I figure it was only causetbey couldn't drive but still. I wish I had that car to this day what a fun little car the only time I had a problem was when the fuel pump went out and after I replaced it which was so simple cause it's right under the driver's seat of course not in the interior compartment but anyway it wouldn't run and my mechanic couldn't figure it out and it sat for about four months and one day I was driving and it dawned on me there's a secondary fuel pump in the actual gas tank it costs me five dollars and took ten min to swap out I just logged the hatch and twisted the cover off and pulled it straight up and dropped the replacement in and it started right up I was a little annoyed that I didn't think of that but I was only 19yrs old then lol anyway great FN car great year too

ST3V3N36 wins the internet's longest sentence award.