To delete or not to delete - the stats

Discussion in 'Non Technical' started by misszen, Jul 9, 2012.


Would you delete the following optional items yourself?

  1. Delete PVCR

  2. Delete EGR

  3. Delete under plenum coolant bypass

  4. Delete AIV's

  5. Delete HICAS

  6. Delete exhaust sensors (not the 02's)

Multiple votes are allowed.
  1. misszen

    misszen Red ones go faster!

    Rather than ask opinions and get every answer I thought it is more appropriate to see what the actual stats are when it comes to deleting items and see where it all lands.

    Would you delete the following or not?
  2. ryzan

    ryzan Black Mesa? Fat chance...

    All these deletes have been well documented in the past, listing their advantages and disadvantages. Do a search and you will find all the information you need plus more.

    I will say though, there's a reason so many people do the deletes.
  3. Mike

    Mike New Member

    I am deleting/deleted everything on that list cept the hicas and the exhaust bits. has a run down on some of those deletes and the pros and cons and long term analysis.

    My primary reason for most of the deletes ? Less things to get boost/vacuum leaks from and the underplenum rats nest coolant leak preventation.
  4. stumagoo

    stumagoo Active Member

    the cat sensor and the egr was already done I have done the under plenum and aiv and am looking into hicas as well. the las is mainly as I am cleaning up the engine bay and not sure if I want the hicas in there. Also the inner ends of the hicas tie rods are stuffed on my car.
  5. MagicMike

    MagicMike Moderator Staff Member

    Delete them all. Or wait til the f up and then delete them.
  6. misszen

    misszen Red ones go faster!

    Stats are interesting already

    These stats are interesting already - 50/50 on the hicas so far and 100% under plenum bypass
    Last edited: Jul 9, 2012
  7. ABZ300

    ABZ300 G

    Ive had everything deleted except for HICAS (mine's NA) and the exhaust sensors...whats the benefit of deleting the exhaust sensors? Ive never heard of anybody doing that...

  8. misszen

    misszen Red ones go faster!

    Comes from when you install a new exhaust and there is no ports for the sensors except 02 - the decision is made to either put in ports or delete the exhaust sensors - I dont think there is any benefit except for saving time and $ by not putting in the extra new ports.
  9. michandy

    michandy Active Member


    In my opinion the Hicas delete is more a personal preference thing, from all accounts though it can be quite scary when it goes wrong. I'm not saying that it will go wrong just that it could, it is after all a 20 year old system that has more than likely had no maintainance done on it!.
    If you do the delete, remember that it is a part of the vehicles steering system and treat it accordingly!, use quality parts!. I say this because you don't want it to fail.
    Hope this helps, Andy :cool:
  10. Hidds

    Hidds THAT annoying guy....

    easiest thing in the world, under plenum, while your doing that a few other deletes come out easy
  11. misszen

    misszen Red ones go faster!

    The stats are telling the story - thanks all

    Yeh - I was wondering whether it would get about 90+% for the under plenum but 100% surprises me and pretty much confirms that it is absolutely useless unless you live on the russian front. Besides you get extra water cooling pressure to the turbos from deleting that birdsnest of pipes not to mention the less that can go wrong under there.

    If your drifting or racing then the hicas is normally deleted but for a normal street/ touring car you just cannot replace those counter forces from the 4ws with anything else when your high speed maneouvering. I always thought it was even in opinion but the stats are now tipping towards keeping hicas it would appear. I dont believe maintenance is a real factor to delete given the whole car is twenty years old and requires maintenance all round, to own a Z, you have to appreciate that and accept it as part of the love that goes with owning one anyway like any other part.

    EGR/ AIV's depends on whether you want economy and better starting or extra carbon and gunk to deal with, I think it will take more votes before we see a steady result on for those on whether to delete or not , but I am really surprised so far that the delete for them is so high and dominant!

    Thank everyone for voting - the stats tell the real story at the end of the day on whether it is better to delete or not, as compared to the vastly different opinions that often conflict in the threads - where people are asking whether to delete or not.

  12. Wasgood

    Wasgood New Member

    Wouldn't this throw off the fuel mixture?

    (Or maybe I'm thinking of the O2's.)
  13. Anti

    Anti 14.7 x 14.7 = 44.1

    All of them, CTS (cat temp sensors) are optional but mine went when aftermarket cats went in.
  14. misszen

    misszen Red ones go faster!

    I think your referring to the O2's
  15. Wasgood

    Wasgood New Member

    The exhaust sensors just measure the tempreture of the cats then.
  16. misszen

    misszen Red ones go faster!

    yep - they have no correlation to the ECU input engine adjustment factors as such.

    The EGR is almost a 100% delete - that is so surprising!

  17. OZX_320

    OZX_320 Detachable Member

    You ever pulled off an old EGR system? Pipes are that full of crud that there is no chance it hell that it operates anymore.
    Delete- less vacuum lines to EGR solenoid, valve and pipes to plenum underside.
    - makes it a lot easier to remove and refit plenum

    Cat temp sensors- unless youre fitting an aftermarket exhaust, no real need to get rid of them, unless your car is substantially lowered. If they cop a hit, it tears the outer sheathing, causing intermittant illumination of the warning light.

    AIV's and PRVR- delete em

    Plenum hoses- surprised youre even asking, even more so that you havent done them already.

    HICAS- if its working, and you arent on a mission to de-clutter your engine bay, leave it.
  18. misszen

    misszen Red ones go faster!

    My EGR is still working fine??
    less vacuum lines means nothing unless your too lazy to do a boost leak test - lol

    AIV/ PVR - your 70% right based on the stats

    Plenum hoses - I actually have deleted them - 100% have deleted as well in stats, so I would be more surprised if anyone does have them still (possibly a sign that servicing hasnt been according to plan - injectors/ 200k etc?)

    I think your about right on everything else said and its certainly easier to refit plenum

  19. mr zed x

    mr zed x chassis scrubbin..

    all of them.
    IF they even work, they are useless and bound to fail.
  20. Jinxed

    Jinxed Moderator

    remove the lot, remeber on most cars all these systems are 20+ years old!

    some are obselete, some are pointless, some are dangerous and they are ALL a liability

    engine bay looks SO much better minus all that crud as well.....

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