Increased O2 levels in my Zen Estilo’s PUC check: Now what?

My car is near the 80k mark and is running fine. The fuel efficiency and pickup seem to have reduced a bit.

BHPian dailydriver recently shared this with other enthusiasts.

Please refer to the O2 values ascertained during PUC checks of my K series Estilo for the past four years. The sudden spurt in O2 levels strikes me as odd.

  • Do I need to check the sensors for any faults?
  • The fuel filter is due for replacement. Would changing this bring back the O2 levels?
  • Is my engine is running lean?
  • Is the current O2 level in excess of normal values?

I randomly checked the O2 levels of similar vintage petrol vehicles and most of them hover between 4-15 PPM: mostly towards the higher end.

My car is near the 80k mark and is running fine. The fuel efficiency and pickup seem to have reduced a bit, but those could be the effects of clutch wear (still original). But of late, I seem to feel that the engine bay gets hotter – this is just a feeling and not based on empirical observation.

Here’s what BHPian Jeroen had to say on the matter:

Although in theory your engine looks like it is running a little more lean, these are still tiny tiny values. Nothing to worry about. Did you check the calibration of the analyser used? Calibration being off is probably a more likely cause.

If there was a real problem with running lean, your check engine light would have come on.

Fuel efficiency is not really affected by your clutch. A clutch slipping will go from a little bit of slipping to not working at all very quickly.

Fuel filter should not have any major effect. If you feel the car is a bit sluggish, I would always check the air intake filter first. In a dusty environment such as India, it can get clogged up really quickly. And it will negatively impact fuel efficiency and performance.

Never ever start replacing stuff, unless you have a proper diagnosis, which means as a bare minimum hooking the car up to a brand/model specific OBD scanner and see what codes there are. A good scanner will also provide you with the fuel trims and possibly even lambs values. Takes all guessing out of the equation. You do need somebody that of course knows how to interpret the various values.

Good luck


Read BHPian comments for more insights and information.

Source: Read Full Article