Engine Egr Code 33 Easiest Fix?

Discussion in 'Fox 5.0 Mustang Tech' started by 90lxwhite, Dec 28, 2013.

  1. If y'all were betting gents what would y'all think would be the cause? Could cleaning it be the fix? Maybe the egr position sensor?
    Ps: I think its making me fail emissions.
  2. Code 33 - Insufficient EGR flow detected.
    Look for vacuum leaks, cracked vacuum lines, failed EGR vacuum regulator. Check to see if you have 10” of vacuum at the EGR vacuum connection coming from the intake manifold. Look for electrical signal at the vacuum regulator solenoid valves located on the rear of the passenger side wheel well. Using a test light across the electrical connector, it should flicker as the electrical signal changes. Remember that the computer does not source any power, but provides the ground necessary to complete the circuit. That means one side of the circuit will always be hot, and the other side will go to ground or below 1 volt as the computer switches on that circuit.
    Check for resistance between the brown/lt green wire on the EGR sensor and pin 27 on the computer: you should have less than 1.5 ohm.

    Backside view of the computer wiring connector:

    See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)



    EGR test procedure courtesy of cjones

    to check the EGR valve:
    bring the engine to normal temp.

    connect a vacuum pump to the EGR Valve or see the EGR test jig drawing below. Connnect the test jig or to directly to manifold vacuum.

    Do not connect the EGR test jig to the EVR (Electronic Vacuum Regulator).

    apply 5in vacuum to the valve. Using the test jig, use your finger to vary the vacuum

    if engine stumbled or died then EGR Valve and passage(there is a passageway through the heads and intake) are good.

    if engine did NOT stumble or die then either the EGR Valve is bad and/or the passage is blocked.

    if engine stumbled, connect EGR test jig to the hose coming off of the EGR Valve.
    Use your finger to cap the open port on the vacuum tee.
    snap throttle to 2500 RPM (remember snap the throttle don't hold it there).
    did the vacuum gauge show about 2-5 in vacuum?
    if not the EVR has failed

    EGR test jig

    The operation of the EGR vacuum regulator can be checked by using a test light applied across the wiring connector. Jumper the computer into self test mode and turn the key on but do not start the engine. You will hear all the actuators (including the EVR vacuum regulator) cycle. Watch for the light to flicker: that means the computer has signaled the EGR vacuum regulator successfully.
  3. Egr vac regulator then... Crap vac leaks I don't wanna chase that. 'twas hoping for a part swap/sensor swap
  4. Seems the reg solenoid is ez. Oh n its never personal /jrichker, always a form letter.
  5. always gets the job done if you follow the advice he listed though!!
  6. You're obliviously not rich, famous, or a beautiful lady in distress. So you don't qualify for a personally crafted exposition of how to fix your problem...
    #6 jrichker, Dec 29, 2013
    Last edited: Dec 29, 2013
    Mustang5L5 likes this.
  7. Obliviously... image.jpg
  8. Does your car have an EGR that should be functional?

    I only say this because countless guys here delete their EGR's and then experience issues down the road. So even though the sensor is there, was anything done to disable it internally? Like explorer intake without the EGR passages? or heads that don't have the provisions?

    EGR robs 0 HP, and does help with part throttle crusing fuel economy.
  9. Stock heads, stock intake. I've never messed w the egr so I'm assuming it should be working, unless the previous owner did something w it but its on there. On a side note: if I go explorer intake I have to disable egr? Would it be emissions legal you think if I went that route? I was considering the swap.
  10. If you got an earlier Explorer intake, you could keep the EGR functional. The provisions were there for the 96-97 Explorer. You would just have to make sure to pick up an explorer intake from this year span. Shouldn't be too difficult. There are other reasons to choose this intake over the later model explorer intakes. Thicker boss where you much drill/tap for the ACT, as well as thicker mounting flange for the upper intake to bolt to the lower. The later models tend to be cast a little thinner and crack.

    EGR needs to be functional if they perform a sniffer test. It does have a role in emissions.
  11. Thank you sir. One more thing while I have you on the line; Do aftermarket intakes like tfs, eddle, or the "cobra" knock-off have provisions for egr or would one have to fab something up?
    #11 90lxwhite, Dec 30, 2013
    Last edited: Dec 30, 2013
  12. Some do, some don't. I know the Cobra has it, unsure which of the aftermarket intakes do.

    Do you have one in mind?
  13. Ah not really at the moment, prob wait on heads but on my 95 I had the lower ported and picked up a decent gain. Went from 205 to 223 horse. But when it comes time to do the fox I wanna find one that's pretty much "plug and play"