high emissions MOT failure

[Mark]

Like an idiot i found a cheap alphard 2.4l e-four hybrid with issues i thought i could fix engine management light was on as was red engine light with ! throught it found a fault code reader for £100 iCarsoft i905 Fault Code Reader Toyota / Lexus / Isuzu works a treat .Anyway the hybrid system didnt seem to charge and then had burning smell coming from under passanger seat , pulled the hybrid socket and disconnected the battery , went through YOUTUBE  looking for hybrid battery repair didnt look to hard so off i went ,seats out centre console out seat bracket out finally got to hybrid batttery anyway to cut a long story short one of the 30 batteries had go bang and blown a small hole in itself  and slightly damaged the one next to it no probs ordered two replacements no probs refitted it back together leaving seats and frame out just in case and gingerly turned the key everything to my surprise worked checked everything all good cheap fix for the first problem only £48. the next problem is MOT failure with high emissions ive changed o2 sensor fault code of P1346 vvt camshaft sensor, changed this as well, the orange engine management light comes on after a few minuites after start up and goes out after the ignition is switched off .Could there be an underlying problem with the camshaft or the wiring loom im running our of ideas , thinking of putting another  cat in to help reduce the emissions  just to get it throught the MOT my patience is wearing a bit thin its a lovely motor and all i want is it on the road hopefully someone out there may have some ideas 

[MonsterS]

There are two sensors one front and one back of the exhaust. Have you changed both?

[Mark]

just the front one  advise from garage was to use only oem parts is this correct will cheap copies work as well as 

[Mark]

have also changed the camshaft sensor but it is still showing p1346 fault code any ideas 

[MonsterS]

As a matter of point for these always change both and yes genuine parts always on my list.

[Mark]

lambda and o2 sensors have now been changed as said before crankshaft sensor changed have disconected battery left it off over night cleared any fault codes and started afresh wasnt long after starting orange engine ligth came on showing o2 and vvt camshaft sensor faults 

It went into garage to have new steering rack bushes fitted and although thje management light was on no fault codes were showing on their  machine 

[Bazbro]

Check all connectors... (a real pain, I know!).  Use a dialectic electrical spray (Halfords or t'internet).  If you're lucky, it might just be that. 

Do it methodically, the obvious ones first, particularly any that have been recently disconnected or near where you've been working.  A cheap fix if that's all it is!  Good luck.