Poorly mk4 gti

[Norfolknudger]

Hi all I bought my golf early last year and have run around in it happily until recently she's been modified air intake decat remapped to 212bhp when I first had her she had a small occasional back fire  but recently it's started to over fuel with plenty of backfiring and she also seems to be choking  under throttling and missing I've changed the airflow meter the lamba sensor as its been decated it only has 1 and I've changed spark plugs but still no joy so I changed the ecu clocks and ignition barrel ran loverly till she got warm then started to choke itself again can anyone help as I'm lost now cheers all will 

[beppe2672]

Mate you need to get it scanned for fault codes!

[Norfolknudger]

Hi fella got it plugged in came up with temp sensor so replaced it with a new one but still not rite but is better also found top alloy intake pipe from intercooler had worn a hole in itself rubbing against bulk head I think by the time I've finished the old girl will have had a rebuild

[Dalo Harkin]

From what you have given as symptoms check:-
Plugs
all boost pipes
maf

And go from there as any of the above can cause the symptoms you described, plugs would be the obvious one first to try