Intake Manifold and EGR Cleaning/Replacement - How hard is it really?

Options, as needed: your existing EGR valve could be fine. Not that hard to clean either. The cooler is tougher to clean but doable as well, if it comes to that.

 

The most expedient oil catch can connection is to cut the existing PCV hose at the middle, push on 3/8” brass barb splicers (PEX connectors work as well, and are more easily removable as needed), push 3/8” ID fuel line (SAE-J30R7 or …R6), run those to your oil catch can inlets and outlets.

To return the system to stock, a replacement hose is about $10 USD, part no: 12261-37060. It’s item 12661 here.

I went “upmarket” some on my OCC, have dual Moroso 85474 Air/Oil separators. They’re pricey though, and getting more so.

Lots do mount by the drivers headlight; I opted for below the intake manifold, on a bracket atop lower cross beam (front jacking point beam. They’re bottom draining, most practical access during oil change:

 

Looks like I’ve reiterated what’s mostly covered here.

 

The comparison I keep wanting to see is how the revised Toyota valve compares inside to the original Toyota valve.

So far, everybody who has bought one of the revised ones has been like, "not me, I'm not opening the cover on this valve I just bought!".

 

I tried one once and it took a no code original egr to a P0401. It would stick open right out of the box. I did not take it apart to avoid trouble returning it. It went back and the updated Toyota version went in.

From an Amazon review:

 

Yeah, that's the inside of a cheap knockoff. We've seen those before.

There is a genuine Toyota-issued update to the original Toyota EGR valve. We know it's physically a bit larger and the wire harness needs to be untaped a little for the plug to reach.

That's the one I'd be interest in seeing inside pictures of.

 

I wouldn't use purple power: it's caustic, and there are corrosion-prone metal embedments in the intake manifold. I did an oxi-clean soak one time (it's mildly caustic), and when I had the intake manifold off again, about a year later, all the embeds, and some of the hold-down nuts, had crusty corrosion. I brushed them off and well, spritzed WD40 on them, and resolved to reserve caustic cleaners for the egr cooler only, which is stainless steel. Caustic cleaner could be used also on the EGR pipe (between EGR valve and intake manifold), but it's overkill, a very easy cleaning chore with brake cleaner.

What you can do in advance, any time, is remove the EGR cooler lower bracket nut and stud [1]. It's time-consuming, simply due to access, hoses and whatnot in the way. You need just the right combo of extension and socket, not too long. as you stand at driver's side fender, it's around 3 o'clock relative to a largeish, braid-sheathed coolant hose going into the engine. The nut's 12 mm head IIRC, and the stud requires an E8 torx socket.

Getting to the nut and getting it off took me a concerted 1/2 hour, farting around with a long-handled flex head ratchet wrench, trying various socket/extensions. For the stud I put the E8 socket on a 1/4" ratchet wrench, reached in blind. It was tough to break loose, and tough all the way backing out. With limited room it was one click at a time. Keep it pressed very firmly on the head of the stud, and go cautiously. It seemed like it was going to round the head the whole time, for me.

With that done, you can extract the cooler without removing the rearmost pair of studs [4], and they will prevent the gasket from dropping down, and align it during the subsequent install.

Just leave that EGR lower bracket nut/stud combo off, permanently. For the other EGR valve and cooler nut/stud combo [2] and bolt [3], if you've got the time I'd remove and reinstall them, with a dab of anti-seize, also in advance.

 

I would disconnect the 12v for sure. It is still hot all over engine compartment even with the car shutdown, unlike the high voltage.

On a v I don't have any resets or issues after unplugging the 12v. Sometimes it takes 2 or 3 start attempts simply because they don't know to begin with the ignition On state for 30 seconds before pressing the brake and Power to get a Ready. The initial On state allows the ecus time to start up after power restoration.

The real downside of leaving the 12v connected is the possibility of discharging the battery with doors open etc. Then a jump could go bad with the inaccessible 125a fuse and six others blowing. Then it's tow truck time.

 

Regarding the 12 volt disconnect: the Repair Manual makes no mention of it. As far as running the battery down, only the hood need be open for the whole procedure. FWIW, I typically have ours plugged into a smart charger, anytime it's in the garage (belts and braces).

 

I checked what it is we've got under the bathroom sink. Ostensibly lye, purchased for a soap making project that has yet to happen. Lye is Sodium Hydroxide (NaOH). What we had in fact was Potassium Hydroxide (KOH), and looking it up, I see it's very similar in efficacy.

I did try it to clear a bathroom sink, and it seemed to behave very similarly. It'll likely be my cleaner of choice, if and when there's a next time. I'd hazard either NaOH or KOH will be very effective, for carbon socked-in cooler.

If you opt for such cleaner, do read up on it and use safety precautions. Say gloves, old, long sleeved shirt, goggles. Read up how to mix, proportions. Have a well ventilated area. Have vinegar on hand, to neutralize in case of spills.