Would it be safe to assume that I need a new front o2 sensor? I got the suspicion when my mpg went down and the car started running like a bag of doughnuts when in boost. I'm looking at the walker one from oxygensensors.com for $64. Are there any other reliable aftermarket ones? I can't afford the $290+ dealer part.

P0125 - insufficient coolant temperature for closed loop fuel control
P0130 - o2 sensor circuit malfunction (bank 1 sensor 1)
P0135 - o2 sensor heater circuit malfunction (bank 1 sensor 1)
P0300 - random/multiple cylinder misfire detected

recently installed a new thermostat and rear (ecu) coolant temp sensor
no coolant leaks
afr's at idle start out at 11.5ish, and up to 14.2ish at operating temp
*the rear o2 hasn't been deleted nor tampered with in evoscan. I'm put a spacer on it about 5 years ago and it hasn't thrown a related CEL since*

evoscan readings while idling:
fuel trim low - 0%
fuel trim mid - 0%
fuel trim high - 0%
fuel trim in use - 0%
oxygen feedback trim - 5.078125%
coolant temp - hits max at 203F (95C), fans kick on and lowers temp
oxygen sensor - 0.0v
oxygen sensor #2 - 0.7v

 

Your O2 shouldn't be reading 0V. It should flip back and forth between 0.2v and 0.9v.

The oem sensor is made by Denso. Here is a link to the Denso O2 sensor on Amazon for $55.

http://www.amazon.com/gp/product/B000C5SGEU

 

Outstanding, thanks!

 

For the P0130 and P0135 codes a new front O2 sensor is definitely what you need. I don't know about the other codes.

290+ from the dealer? That's a bargain compared to the 699+ (NZD) I got quoted from my local dealer, for the part only.

I went for the walker one off oxygensensors.com, have been using it for 5000km + so far and it's doing the job. The factory denso one got over 60,000km. There's no need to purchase from a dealer.

 

is this the same as the 02 sensor used in the evo??

 

Yes sir. Front o2 for an evo 8 is MN153010 = Denso 234-4741
Front o2 for an evo 9 is 1588A064, but Denso's website doesn't show a cross referenced part for that one.

 

So the Denso front O2s for the evo 8 and 9 are different?

The walker ones are the same (according to oxygensensors.com), kind of strange.

 

Not sure, but they do have different oem part #'s. The customer reviews under the denso 234-4741 on amazon states that it works for the evo 9 o2 as well.

 

your front o2 is dead. I had similar Symptons (Couldnt log Fuel Trims, 11.4 cruising afr)

any who, i got my sensor from a local parts shop for 70 bucks. I think autozone can get them for 70 ish also

 

I got mine at oxygensensors.com

This time I bought the version with the oem wire harness plug on it. Last time I used the universal, just got lazy for the 30 bucks. Either work great, and any of them will eventually fall out of spec, especially with higher power and stress.

https://www.oxygensensors.com/catalog.php?&pkey=1432585

 

double post.

 

So, today I take the spark plug cover off only to find that the o2 sensor had became unplugged the other day when I took the spark plugs out to regap them. All I could do was laugh at myself. Derr.

 

Lol

 

just got quoted $784 from Canadian dealer in Edmonton

 

This thread is funny, keep those super price quotes rolling in.

(I feel for you bigben LOL)