P1074 Code--'03 Mazda MPV

[ET16]

I got this code (too lean, bank 2) for the first time last week. Cleaned the MAF sensor, cleared the code with my scanner, but it came back a few days later. I don't see anything amiss with any vacuum hoses. Anything else I should look for?

Thanks!

 

[ItsuMitsubishi]

Maybe it's time for some O2 sensors

 

[ET16]

Originally Posted By: ItsuMitsubishi
Maybe it's time for some O2 sensors


I hadn't thought of that. I've got 66k on the van, so it would be a little early.

 

[bepperb]

It's one MAF but two O2 sensors, and only one sensor is reading incorrect? I'd assume the o2 then.

 

[bdcardinal]

O2s are pretty common on those. Sell a fair amount of them.

 

[ET16]

Originally Posted By: bdcardinal
O2s are pretty common on those. Sell a fair amount of them.


That's interesting. I guess I'll have to take a look. I have a tool for removing O2 sensors, but I don't know where they are on this car. I imagine I'll be able to find them easily enough.

 

[bdcardinal]

Originally Posted By: ET16
Originally Posted By: bdcardinal
O2s are pretty common on those. Sell a fair amount of them.


That's interesting. I guess I'll have to take a look. I have a tool for removing O2 sensors, but I don't know where they are on this car. I imagine I'll be able to find them easily enough.


The EGO sensors are both fairly easy to find up on top, the cat monitors you need to look under the vehicle.

 

[Vikas]

Do you know if you wait long enough, will you get the similar code for the other cylinder? Either that or put a scanner with live data on it to find the STFT and LTFT of both the banks and see if they are approaching 25% or over. Often, both banks would be running lean but only one would trip the threshold. If that is the case, MAF would a be better shot it the dark as replacement candidate No, seriously, you will be able to look at the MAF readings on the same scanner to ascertain if it is working or giving low air mass readings.

If you don't want to do that, just replace all O2 sensors, MAF sensor, spark plugs, air filter, catalytic converters etc etc; something or other is bound to fix the vehicle

- Vikas

 

[ET16]

Originally Posted By: Vikas
Do you know if you wait long enough, will you get the similar code for the other cylinder? Either that or put a scanner with live data on it to find the STFT and LTFT of both the banks and see if they are approaching 25% or over. Often, both banks would be running lean but only one would trip the threshold. If that is the case, MAF would a be better shot it the dark as replacement candidate No, seriously, you will be able to look at the MAF readings on the same scanner to ascertain if it is working or giving low air mass readings.

If you don't want to do that, just replace all O2 sensors, MAF sensor, spark plugs, air filter, catalytic converters etc etc; something or other is bound to fix the vehicle

- Vikas


I am a little worried about throwing parts at this problem. I'll look around some more; I think that the pcv hose is worth a closer look. Unfortunately, I don't have a real time scanner to go into the other things, just a cheap one that reports stored codes.

 

[Vikas]

Without real data, you will always be throwing parts at it. Do you have factory service manual for it? If so, you might be able to hook up DVOM to MAF and see if it is reporting right data. To check O2, you will need oscilloscope which I am not sure who among BITOG has one.

Given that you have ruled out all the vacuum leaks, MAF and/or O2 sensors are the two possible candidates for replacement.

I am curious about how you proceed from here. Personally, without live data scanner, I would wait for a while until the second bank code pops up. If it does, then you can condemn the MAF.

I would suggest you watch few youtube videos from "realfixesrealfast". He is the *best* when it comes to systematic and 100% no parts thrown diagnostic work. He is the type of the person who puts a multimeter on a visibly broken wire before condemning it He has bunch of videos on lean code vehicles.

- Vikas

 

[bepperb]

Both O2's and the maf probably cost less than paying a shop with a 10,000 dollar scanner to replace just one. "Throwing parts at it" might not be elegant, but is often the least expensive option. A MAF may be a part you can buy and return if it isn't the problem. An o2 really isn't going to look new after the fact.

Best of luck.

 

[Vikas]

I do think that given a scanner can be purchased for as low as under $100 dollar, you recoup the cost in a single visit to the shop.

- Vikas

 

[ET16]

Originally Posted By: Vikas
I do think that given a scanner can be purchased for as low as under $100 dollar, you recoup the cost in a single visit to the shop.

- Vikas


Vikas,

Would this be a real-time data scanner? I thought that these were much more expensive. Any recommendations?

 

[rat]

More often than not, a P0174 code indicates a vacuum leak, likely the PCV elbow, sometimes intake gaskets. Check these before wasting money on oxygen sensors.

 

[Vikas]

Originally Posted By: ET16

Vikas,

Would this be a real-time data scanner? I thought that these were much more expensive. Any recommendations?


Yes; as a matter of fact somebody from BITOG purchased one recently on my recommendation. It is from Harbor Frieght and on sale and after using 20% coupon was under $100 or thereabout.

http://www.harborfreight.com/can-obd-ii-code-reader-eobd-scanner-98614.html

Description of Cen-Tech 98614

Now you can find out what’s wrong with your car...no need to go to a dealer or repair shop. This CAN OBD II Code Reader/ EOBD Scanner “reads” your car’s computer to tell you what the issues are. Your vehicle’s OBD II system monitors emission control systems and key engine components by performing either continuous or periodic tests of specific components and vehicle conditions.

* For use with 1996 and newer vehicles sold in the U.S.
* Reads live PCM (Powertrain Control Module) data stream
* Graphs data
* Reads and clears trouble codes
* Views freeze-frame data
* Displays live O2 sensor data
* Easily determines the cause of the "Check Engine Light (MIL)"
* Performs modules present test
* Prints data via PC
* Backlit, 128 x 64-pixel display with contrast adjustment
* Includes user’s manual, CD, OBD II cable, USB cable, 9V battery, carry case

9 volt battery included.
Overall dimensions: 3.74" W x 7" L x 1.5" thick
Shipping Weight: 2.2 lbs.

 

[Vikas]

Another thing, make 100% sure that you do not have a vacuum leak. Use propane to check. You can also use carb cleaner if you are careful not to spray on hot exhaust!

- Vikas

 

[bepperb]

Wow Vikas, I guess I didn't know how much the price had dropped. I guess I haven't looked in 10 years, though. Looks like 100 bucks would easily buy you some live data. Maybe you gave me one more thing to put on my christmas list?

 

[ET16]

Originally Posted By: Vikas
Originally Posted By: ET16

Vikas,

Would this be a real-time data scanner? I thought that these were much more expensive. Any recommendations?


Yes; as a matter of fact somebody from BITOG purchased one recently on my recommendation. It is from Harbor Frieght and on sale and after using 20% coupon was under $100 or thereabout.

http://www.harborfreight.com/can-obd-ii-code-reader-eobd-scanner-98614.html

Description of Cen-Tech 98614

Now you can find out what’s wrong with your car...no need to go to a dealer or repair shop. This CAN OBD II Code Reader/ EOBD Scanner “reads” your car’s computer to tell you what the issues are. Your vehicle’s OBD II system monitors emission control systems and key engine components by performing either continuous or periodic tests of specific components and vehicle conditions.

* For use with 1996 and newer vehicles sold in the U.S.
* Reads live PCM (Powertrain Control Module) data stream
* Graphs data
* Reads and clears trouble codes
* Views freeze-frame data
* Displays live O2 sensor data
* Easily determines the cause of the "Check Engine Light (MIL)"
* Performs modules present test
* Prints data via PC
* Backlit, 128 x 64-pixel display with contrast adjustment
* Includes user’s manual, CD, OBD II cable, USB cable, 9V battery, carry case

9 volt battery included.
Overall dimensions: 3.74" W x 7" L x 1.5" thick
Shipping Weight: 2.2 lbs.


Great!

 

[ET16]

Originally Posted By: rat
More often than not, a P0174 code indicates a vacuum leak, likely the PCV elbow, sometimes intake gaskets. Check these before wasting money on oxygen sensors.


That's my next task. The PVC system is notorious on these cars.