my check engine light is not on but i believe the owner before me removed the bulb because i hooked up my scanner and got these codes:

P0133(o2 sensor circuit slow response bank 1 sensor 1)
P0401(Exhaust Gas Recirculation Flow insufficient Detected)
P1401(DPFE sensor high input)

if any one tell me what all these mean and how to fix it that would be greatly appreciated.

My truck is a 1999 Mazda b2500 4 cylinder 5spd btw...

 

You have a bad upstream O2 sensor and a bad DPFE.
Looking at ~$100 in parts, plus ~$15 for the O2 sensor socket if you can't get a wrench on it (typically can't).

The CEL should come on when you turn the key to Run, before cranking.
If it doesn't, check fuse #17 in the cab. If your cig lighter is inop, the fuse is blown. They share that power.

 

ok thanks.. which o2 sensor is that because there is one on the manifold and one after the cat.. and also where are these parts located and is it hard to repair?.. today is my only day off so i need to get this fixed..

 

That O2 is before the Cat. You should also check your HEGO fuse, under the hood.

The DPFE is usually on the intake, but yours appears to be by the intake rubber tube near the throttle body. It is usually mounted with two 8mm bolts.

Don't mix up the two DPFE hoses. Inspect the two hoses and the metal tubes they attach to for holes/cracks. The hoses are special silicone high temp, NOT normal AP store vaccum hose. Get them at Ford if they are bad.

Reset the computer after replacing the DPFE and O2 sensor.
Let it idle 5 min in P then 5 min in D, then drive normally. This step is not crucial but will help it re-learn a good idle. Add 5 min in P and D with the AC on if equipped.


Neither of these problems is a dire emergency. Your gas mileage will suffer, that's about it. Might not run good at light throttle steady speeds.

The O2 sensor is the harder of the two parts to change. I'd guess 20 minutes tops if you need the special socket.

The DPFE couldn't take 10 minutes if you took a beer break 1/2 way through.


.

 

alright thanks alot im going to head to the auto parts store in a few..

yeah it does kind of sputter in the mornings and have a lack of power for a little n\bit but then typically drives normal after its been running a little while... im glad you included the beer break because so few people do that in their repair time estimates and as we all know it is an essential part of the vehicle repair process..

another question, if i were to take out the cat as i originally planned could i use the rear o2 sensor in place of the one on the manifold since once i remove the cat it will throw a code anyway?

 

No. Leave the forward O2 as is. They are different part numbers.

You gain NOTHING performance-wise by removing the Cat, in any case.
Its removal will just add pollution.

If that's "your plan", I'm sorry I bothered helping you. Good day.

 

No I don't want to remove the cat.. I learned that lesson on my old f150.. I would like to keep it pretty much stock because this is my daily driver. So would you suggest going ahead and replacing the upstream o2 and the dpfe sensor?

 

i just bought the new parts and the new DPFE sensor is plastic but the one on the truck is metal.. im letting the motor cool down before i change out the parts but it just seems like plastic that close to the motor would just melt..

 

The plastic is the standard replacement part.


http://www.tomco-inc.com/Tech_Tips/ttt35.pdf

 

oh ok. the dpfe sensor was fairly easy to replace and the hoses looked good.. i couldn't get the o2 sensor to budge, ill try to make some time to go at it again tomorrow..

after resetting the computer im still getting the P4101 code..
oddly the o2 sensor code has not popped up yet and thats the part i did not replace yet..