Drops to low idle after boost

[Flspeed]

I think that I have a vacuum problem but not sure. I just bought my MSP and love it but if I get into the boost hard in first gear then put the clutch to the floor the rpm's will drop to a point where the engine wants to die and then its settles out. I hope someone here can help. Thanks.

 

[ChopstickHero]

boost leak? you running stock bpv?

 

[Flspeed]

Yes, I was looking and found one leak but could not find any other. When I went to pick up the car today the vac hose was not hooked up to the bpv. When I gat some time I am going to go through the entire car front to back. This is my first mazda so I am not to fimiliar with there setup. I got this car for $9000 with 47000 miles which was under nada so I think I still got a good deal but this vac leak is pissing me off.

 

[frenchy92005]

use some carb cleaner to find the leak. does it try to die at idle?

 

[Flspeed]

Yes, but only when I give it gas real hard or get into boost and floor the clutch then it tries to die but only momentarily and then it goes back to idle. it idles fine otherwise.

 

[Flspeed]

Ok, now I got a cel but I dont know how to read the codes.(scratch)

 

[junya1985]

Ok, now I got a cel but I dont know how to read the codes.(scratch)

Go to autozone they pull codes for free or buy a code reader you can buy them for pretty cheap now


http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94169
$40.00

 

[Flspeed]

Ok, I got the code read. P0421 I am going to do some research but if anyone knows what is going on with this some info would be appreciated. Thanks.

 

[powderider87]

EGR valve or wastegate.

 

[Flspeed]

Well, I have done some research and it looks like most people say the P0421 is a bad cat.

 

[Alejo_NIN]

P0421 OBD-II Trouble Code
Technical DescriptionWarm Up Catalyst Efficiency Below Threshold (Bank 1)

What does that mean?Basically this means that the oxygen sensor downstream of the catalytic converter on bank 1 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.


SymptomsYou will likely not notice any drivability problems, although there may be symptoms. The code may be more likely to occur after the engine has had numerous cold starts in the past 1-2 days.

CausesA code P0421 may mean that one or more of the following has happened:

The catalytic converter is no longer functioning properly
An oxygen sensor is not reading (functioning) properly
A sparkplug is fouled up
Possible SolutionsMeasure the voltage at the oxygen sensor on Bank 1 (the rear sensor, or the sensor after the converter). In fact, it would be a good idea to test each oxygen O2 sensor while you're at it.

One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

did some research too

 

[Flspeed]

I decided to put in the shop at mazda. I want to get all the bugs figured out.

 

[mikeski]

keep us updated....

 

[mazdaspeeeeed]

Im having the same problem with mine. I actually just got the check engine light. I will be cleaning my EGR valve this weekend. where in FL are you?

 

[Flspeed]

Jacksonville, I just picked up this car out of Orlando last weekend.

 

[mazdaspeeeeed]

true. well you should enjoy it. this is my second one and im lovin it

 

[Flspeed]

Ok, I am truely not happy with the Mazda shop right now. Evidently the cat was taken out by the previous owner and because of that the shop will not do any further diagnoses on the drop in idle issue. They see that the problem exist but wont fix it unless the cat is fixed first.(bang)

 

[jdwk]

Shops especially dealer service departments are generally worthless. Guys remove their cats on here all the time, I am sure there is a way to get around the CEL. But you could always get another cat. Don't give up. The drop in idle could be the EGR, but my car's idle drops every now and then as well.

 

[Flspeed]

Yeah, I just read the write up on cleaning the EGR so I am going to try and clean it this weekend. I will definitely keep everone posted.

 

[Flspeed]

I just read up on the non fouler fix. It seems pritty easy but I would like to know how this works. Is it likely that because I dont have a cat that my car is having these problems. I just cleaned the EGR today and it did not help at all.