# Car people: what the hell is this thing? **URL:** \ **Category:** Factual Questions\ **Created:** [February 21, 2021, 1:02am UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371 "2021-02-21T01:02:56Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Kron](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kron/32/12444_2.png) [@Kron](https://boards.straightdope.com/u/Kron)\ **Post date:** [February 21, 2021, 1:02am UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371/1 "2021-02-21T01:02:56Z")
I don’t know what this thing is. It’s the wet/oily cylindrical thing that reminds me of a fuel filter. [![Google Photos](https://lh3.googleusercontent.com/EpwVPyTdVNBRhK1cNsAPV1D7b8kXEED1eVbG2HQBvgmeida6_ABNYKqbAa1QTI8lBWa8e5BfMekzDc9LQ8XMW0LmsiZUvM7ucRV_hXCz_CwN4U5I0dgt7mR5SRD9yLFPIQJrbUxcYg=w600-h315-p-k "New item by Patrick Smalley") ](https://photos.app.goo.gl/b6cwHXYbdvpXRhcs6) It connects to the air intake: [![Google Photos](https://lh3.googleusercontent.com/tQOdvb2_wH5zmOox1uf4WSwMNY-xrBhirgp6PQYjqWC1GcZ6T77fmR43InEx5WqDK4ssol5hReA30tRZWo-xJ2zr1UjYiIQbtsN9Oszijnjt1SmHRsbWz2sqswmHoqRhp6wcx8DijQ=w600-h315-p-k "New item by Patrick Smalley") ](https://photos.app.goo.gl/D761wdpTn6e6AfHE6) I am… not a car guy, generally, and this is the first thing I’ve run into that my Google-fu is failing on. ETA: It appears you may have to click on the photo to see everything; it cuts a lot off for me after posting. ---
**Author:** ![Tabco](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tabco/32/7644_2.png) [@Tabco](https://boards.straightdope.com/u/Tabco)\ **Post date:** [February 21, 2021, 1:41am UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371/2 "2021-02-21T01:41:36Z")
Looks kinda like a vacuum modulator. ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [February 21, 2021, 7:45am UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371/3 "2021-02-21T07:45:58Z")
Car make? model? year? engine type? manual or automatic? ---
**Author:** ![Mr.Me](https://avatars.discourse-cdn.com/v4/letter/m/d2c977/32.png) [@Mr.Me](https://boards.straightdope.com/u/Mr.Me)\ **Post date:** [February 21, 2021, 2:42pm UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371/4 "2021-02-21T14:42:17Z")
PCV valve? ---
**Author:** ![Crankyhillbilly](https://avatars.discourse-cdn.com/v4/letter/c/7993a0/32.png) [@Crankyhillbilly](https://boards.straightdope.com/u/Crankyhillbilly)\ **Post date:** [February 21, 2021, 2:55pm UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371/5 "2021-02-21T14:55:06Z")
That brand K & N is aftermarket I think so it looks like the vehicle has been modified from factory. I vote for some sort of vacuum modulator. If it rattles when shaken then it might be PCV valve. If it is a PCV and doesn’t rattle then it is stuck. ---
**Author:** ![Crankyhillbilly](https://avatars.discourse-cdn.com/v4/letter/c/7993a0/32.png) [@Crankyhillbilly](https://boards.straightdope.com/u/Crankyhillbilly)\ **Post date:** [February 21, 2021, 2:56pm UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371/6 "2021-02-21T14:56:22Z")
If you haven’t already done so might google mod kits from K&N for your make and model and find a parts list. ---
**Author:** ![Kron](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kron/32/12444_2.png) [@Kron](https://boards.straightdope.com/u/Kron)\ **Post date:** [February 21, 2021, 3:21pm UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371/7 "2021-02-21T15:21:08Z")
Thanks for the suggestions! It is a 2004 chevy trailblazer-. Bought it (extremely) used. It is definitely a K & N aftermarket air intake kit… Hopefully this gets me on the right track! ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [February 21, 2021, 3:38pm UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371/8 "2021-02-21T15:38:53Z")
> [@Kron](#): > > It is a 2004 chevy trailblazer-. Bought it (extremely) used. It is definitely a K & N aftermarket air intake kit… Hopefully this gets me on the right track! Was it ever owned in California? It could be some kind of filter or charcoal canister from a kit made to bring a vehicle not built for California in line with California code. I can’t remember when it was that all manufacturers just decided to make all cars California-ready. ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [February 21, 2021, 3:47pm UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371/9 "2021-02-21T15:47:18Z")
OK. I looked at some diagrams of 2004 Trailblazers. I am now voting for [fuel pressure regulator](https://www.stockwiseauto.com/acdelco-217-1445-fuel-injection-pressure-regulator?fit_id=11069&Year=2004&Make=Chevrolet&Model=Trailblazer&gsID=pxf325262f11069&gclid=Cj0KCQiApsiBBhCKARIsAN8o_4iGcqfgYXJEI4SsOPjXY6ZcbQUeDHQZzDimlee9oesEfIegQ0D8uukaAt2vEALw_wcB). ---
**Author:** ![Kron](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kron/32/12444_2.png) [@Kron](https://boards.straightdope.com/u/Kron)\ **Post date:** [February 21, 2021, 3:57pm UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371/10 "2021-02-21T15:57:18Z")
YES! Thank you! ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [February 21, 2021, 4:21pm UTC](https://boards.straightdope.com/t/car-people-what-the-hell-is-this-thing/933371/11 "2021-02-21T16:21:39Z")
If you want a new one, look around. I saw prices from about $16 - $66. You might try Amazon, because they may have more than one brand, and will have customer reviews.