[Crankpin]

My 2014 AT Brio had it's first major issue last week when the MAP sensor failed and the car started having idling issues.

Initially I thought it was a problem with the sensor being dirty/ clogged but after trying out a another Brio's sensor we figured out that the sensor is bust.

I have ordered the ridiculously expensive MAP sensor from Honda but will have wait for a week for it to arrive. I shall meanwhile check both the O2 sensors and try to clean them up.

[palsaumik]

Originally Posted by Crankpin

That's good! What did the pair of o2 sensors cost you? Did you change them yourself?

The upstream O2 sensor was Rs. 14,500 and the downstream one (after the catalytic converter) was Rs. 10,500 (inclusive of taxes for both).

I chose to get them changed at the Honda Service Center. But if you have the right tool, the upstream one can be changed yourself. Its pretty easy since its easily accessible under the bonnet. For the downstream one, I guess the car needs to be lifted on a ramp, else its difficult to pass the wires through the fixed clips.

Hope this helped.

[Crankpin]

Right, so even the O2 sensors are ridiculously priced by honda.
Did you search for aftermarket/ OEM replacement ones before going in for the Honda ones?
Usually the O2 sensors don’t foul up unless the plugs are bust or you have some serious ignition issues or perhaps bad fuel.
Did you check everything else?

[palsaumik]

Originally Posted by Crankpin

Right, so even the O2 sensors are ridiculously priced by honda.

Very true! I checked the prices for Maruti Alto and it costs about Rs. 3000 only (as far as I can recall). Pretty crazy spare part costs I must agree

Did you search for aftermarket/ OEM replacement ones before going in for the Honda ones?

I personally do not prefer any aftermarket stuffs for such critical components. They may be light on the pocket now, but may fail again even sooner. I am a firm believer of Honda and their authorized spare parts, so decide to stick with them.

Usually the O2 sensors don’t foul up unless the plugs are bust or you have some serious ignition issues or perhaps bad fuel.
Did you check everything else?

Everything else was checked and was found to be perfectly OK. Hence I was able to narrow down my problem to the O2 sensors in my case.

[Crankpin]

You get OEM replacement Denso sensors (same ones supplied to Honda) just that you'll have to scout for them.

Also, like in your case, my car's FE had gone down and I knew something was wrong with the intake & it's sensors

Anyways, did you get a chance to hook up a multimeter and check the older O2 sensor/s for resistance? If you have the time and patience, just check your older O2 sensors. No values will mean they are dead. Good ones will show some resistance on the meter.

[palsaumik]

Originally Posted by Crankpin

You get OEM replacement Denso sensors (same ones supplied to Honda) just that you'll have to scout for them.

Also, like in your case, my car's FE had gone down and I knew something was wrong with the intake & it's sensors

Anyways, did you get a chance to hook up a multimeter and check the older O2 sensor/s for resistance? If you have the time and patience, just check your older O2 sensors. No values will mean they are dead. Good ones will show some resistance on the meter.

I hadn't checked for Denso OEM replacements.

I didnt use a multimeter to test the Volts but had used an OBD scanner to check the live readings from the sensors. Upstream sensor was reading ~0 Volts (barely any movement on the graph) and the downstream one was irregular - all during idling.

[tantunain]

Hi Palsaumik,
Thanks for the great thread on analysing the low mileage on your Brio, I'm following up on my Brio, would you have the PUC readings after the sensor change to confirm that the values actually changed and that would also give us a benchmark on what is right and when the numbers are out.

I actually wrote to honda technical support quoting this thread and asking for their opinion on what they suggest to improve a Brios mileage that's at 10 when my Honda City gives me 15kmpl. Regulation reply that if the Honda Diagnostics is clear there is nothing wrong with the sensors and nothing more that can be done to materielly change the mileage other than standard stuff like tyre pr and drive smoothly.

I'm planning to start the investigation with a PUC and then followed by Obds analysis. Two friends are waiting in the wings to see if I succeed they will follow. Will keep this forum posted on this as it proceeds.

[palsaumik]

Originally Posted by tantunain

Hi Palsaumik,
Thanks for the great thread on analysing the low mileage on your Brio, I'm following up on my Brio, would you have the PUC readings after the sensor change to confirm that the values actually changed and that would also give us a benchmark on what is right and when the numbers are out.

A much delayed response, my bad! To answer your Q to the point, I never checked the readings after changing the O2 sensors. But the mileage was back to normal (about 15-18KMPL) consistently, acceleration was back to normal and everything seemed fine. But after about 5-6 months or so, it started going down-south. Mileage dropped back to <8KMPL (measured tankful to tankful) and sluggish acceleration and on top of that, it had both front suspension issues again, sudden car stalling without a reason, etc. So, finally took the decision to exchange it with a brand new Vitara Brezza ZXI+ at Kataria Motors (Bengaluru).