I have a 99 Mazda B3000, the other day, I pulled out a neighborhood got on the gas to speed up, and I had no acceleration, only revs like i was in neutral. little while later, check engine light came on. pulled PO401, I replaced the EGR valve, but i still have a rough idle. It starts high, then after a minute it calms down. Even when I put it in reverse, i have next to no acceleration only revs. can anyone help me diagnose my problem??? thanks guys!

 

Here are the EGR codes the computer can chose from
P0400 Exhaust Gas Recirculation Flow Malfunction
P0401 Exhaust Gas Recirculation Flow Insufficient Detected
P0402 Exhaust Gas Recirculation Flow Excessive Detected
P0403 Exhaust Gas Recirculation Circuit Malfunction
P0404 Exhaust Gas Recirculation Circuit Range/Performance
P0405 Exhaust Gas Recirculation Sensor A Circuit Low
P0406 Exhaust Gas Recirculation Sensor A Circuit High
P0407 Exhaust Gas Recirculation Sensor B Circuit Low
P0408 Exhaust Gas Recirculation Sensor B Circuit High

So why did you replace the EGR valve?

P0401 usually means DPFE sensor is not working like it should, clogged hose maybe, there are two hose on the DPFE, they run to the EGR tube, check them for cracks or blockages
Although DPFE sensors are known to fail, they get moisture inside because they are connected to exhaust system


If you have an automatic trans then its slipping, "high REVs but no movement", is a slipping automatic or a bad clutch in a manual, not an engine issue

Rough idle can be a vacuum leak
After engine is warmed up and idling, unplug the 2 wire connector on the IAC Valve, it will close
Idle RPMs should drop down to 500 or engine may even stall, either is GOOD, it means no vacuum leaks
If idle doesn't drop then you have a leak

 

i pulled the PO401 code. after looking things up, everything was pointing to EGR valve. so it was the first thing i replaced. Nothing was mentioned about the DPFE. SO I'll look into that next. how can i fix this slipping issue???

 

Is it an automatic?

If so then service it and see if slipping stops
All automatics run on fluid pressure, 175psi needed for Reverse, 125psi need for forward.
If seals and gaskets start to leak internally then transmission slips
If solenoids stick then some pressure is lost
During slipping the clutches get warn down as do the Bands(brakes), so not a good thing if it continues

Check fluid, if its darker red then its getting burnt from slipping, smell it for burnt smell.

To check if an EGR valve is OK, get a vacuum hose, sold by the foot, its cheap and good to have around, smaller size, it can be stretched to fit most connections, lol
Put vacuum hose on the EGR valve's vacuum connection
Start engine
There should be NO vacuum on the hose you unplugged from EGR valve, check that, put finger over its end, if there is vacuum then EGR solenoid is bad
Now suck on the other end of that vacuum hose you install on the EGR valve
Engine should start to stumble as EGR Valve starts to open
Stop sucking and engine idle should return to normal
If this doesn't happen then EGR valve is bad or EGR tube is blocked up with carbon

 

My apologies, it is an automatic. And I dont know very much about repairing or servicing vehicles. So I'm not too sure about how to service to check the transmission or even how to manually check my dpfe sensor. all videos and articles i've looked up requires a reader

 

I added to my post

Check the hoses on the DPFE sensor, blow thru them or remove them and check them, there is an ORDER of how they connect so just do ONE AT A TIME

Unplug the wire connector and look at the inside, make sure its clean, plug it back in
Clear codes and see if any come back

 

I think I've found the problem... A video I watched about checking the dpfe sensor, pop the cap off the EGR solenoid, started the truck, put my finger over the bleed, the idle got real low, almost stalling, and smoke was coming from the EGR hose at the bottom going into the engine