engine check light - multiple codes, Vacuum issue ?

[Bassface]

So Newbie here..(Hello all) -  Sorry to start with a brain picking thread - but IMHO thats usually what brings us to these forums in the first place ..

Recently acquired 2002 Rav 4 2.0 for daughter.. CEL on.. OBD suggested MAF (removed and cleaned) - no change. OBD now showing codes P0110 and P0100 and P0161. - Replaced new MAF sensor and lower O2 sensor - Codes clear.. Been on a decent run with no CEL. But CEL returned on a shorter journey. - Code now P1155... Suggesting, upper O2 sensor. 

Inspection reveals that that one looks to have been recently replaced (and I'm not convinced there was anything wrong with the MAF or the other O2 sensor either. I'm not convinced all sensors likely to fail at the same time.

There is evidence that there may have been critters under the bonnet - so I'm thinking this might be a harness issue - though nothing obvious - If thats the issue ... then how best to test ?.. Where best to look ?

I'm more of the opinion that its a vacuum leak somewhere.. Spraying the Carb Cleaner in the pipes hasn't identified where.. Is it worth persisting with this ? - Where most likely. 

I think also it might be related to a spongy brake pedal (it has a new master cylinder and been bled 4 times properly) - Brakes work fine but pedal feel is horrid and not confidence inspiring..

Any ideas as to what to try next ?

 

 

[ernieb]

Sorry I’m not able to help you directly but I have a mate who had rats under the bonnet and they managed to eat the underside of a cable harness without any obvious signs that it had been attacked. He got it sorted eventually but it was a pain in the proverbial. Hope it’s something more obvious and easier to sort.