New-to-me '02 Navi Package - some questions

1. Kinda useless to guess before you get the codes. But...the violent shaking sounds like the steering wheel issue, but you would have probably mentioned the wheel shaking. It also sounds like a car of mine that had a rusted fuel filler neck (from cap to the tank). That happens to cars where it snows a lot. You can see it inside the passenger rear wheel well. Reach up and feel around the back side of the filler neck and especially up over the top right at the body/cap. Snow gets crammed up in that small place and rusts through eventually. Causes a vacuum leak in the tank and can also get water in the fuel.

2. Re: 3...if your AC isn't turning on, which it sounds like, not sure how you could do much about the smell unless you want to take the inside unit out. If you don't know, you don't want to do that if you can avoid it. You'll splinter the dash bezel. Instead, fix the AC and just pump fresh air through. I also pull the entire interiors out of each car I buy, down to the floor metal. Clean everything up.

3. Seems pretty clear that your compressor isn't kicking in. Most likely cause is it's low on freon. Techstream will give you the codes. If you want to know immediately, you can jumper two pins in the OBDII port and the AC controls will blink out the code numbers. I'm sure the instructions can be found searching the archive. Compressor is easy to get to if you remove the plastic cover, which is a little bit of a pain. You can hand spin the clutch, or put 12v on the connector to hear the clutch kicking in. Look for cloudiness in the meter. All the typical stuff. Could be as simple as replacing clutch shims - a few dollars and a few minutes.

 

I've used an ozone machine to get rid of smells and it worked great. I had agreed to carry several boxes of dates from LA to Houston not knowing what those smelled like. Don't ever do that. After two weeks of the odor not dissipating, I borrowed the neighbor's ozone machine and it was gone a few hours later. I've used their machine in my house too. works great.

Looks like they range in price considerably. Theirs looks about like the $80 models, buy it does a big room. Looks like there's a small, $30 model that could work for a car interior.

ozone machine - Google Search

 

Even as early as gen 1, we had the famous Prius drivetrain that turns any misfiring for any reason into violent jackhammering, because of the way the engine and transaxle interact. This article is a classic on the topic, being about a gen 1 that the owner let go for scrap price thinking the violent jackhammering could only be something really bad. With that car, it turned out to be one bad spark plug. In yours it'll just be something among the many things that can cause misfiring.

If this were the gen 3 forum somebody would probably have posted by now that it has to be your head gasket and because of the gen 3 EGR, but as you've seen, even an earlier gen without EGR, and without any reputation for head gasket issues, can still develop misfires for various reasons and still go all jackhammery.

When it happened to my gen 1 I never ended up finding the cause. It only happened every so often and I got 60+ thousand more miles on the car before a Dodge Dakota drove into it.

Yup, that makes sense. The cause will turn out to be any of the things that can cause random misfires. It's just, that's a lot of things.

I've also used chlorine dioxide, as described here, with very good effect. No machine required, just a little packet that gives off the gas.

Find a way to hang it from some string or something in midair in the cabin, not right next to some upholstery where the color could get bleached.

Unless I misremember, the gen 1 HVAC controller doesn't talk on the diagnostic bus, so its codes don't show up in Techstream. You can only ask directly from the HVAC controls and count the blinks. Details on this page:

Blink (a/k/a Flash) Codes – How to. | PriusChat

when you scroll down to "Codes from the heat/air conditioning system" and follow the procedure for gen 1. Code 23 would be a refrigerant pressure issue. Code 22 would be slipping of the magnetic clutch (which only gen 1 had). It only costs about a buck to adjust that clutch and if it hasn't been done by now in a gen 1, it's likely ready for it.

 

Of course, you can always try some simple things, like swapping around the plugs, coils, and injectors to confirm whether the misfire codes follow any of those. Just make sure you clean/blow around those holes so nothing falls in the head when you pull them out.

 

As for the plugs, you can probably get them online for less than the dealer will charge. You +must+ use ONLY the OEM specified plugs: Denso SK16R11 Iridium 3324. These are 90K mile plugs. I've only changed the plugs once, and they were clean as a whistle.

 

I second the idea to only use the iridium plugs. I use NGK IFR5T11, "stock no. 4996", "Laser Iridium Premium". I've never had to replace a coil on mine, so I can't speak to that. The factory manual doesn't give any kind of resistance spec for the coils.

I'm pretty sure that when I've pulled the coils to swap plugs, I've just left the low-voltage connector attached to the coil - possibly except for the #4 coil (furthest from belt, closest to transmission), as its wires don't have much slack.

I know someone that owns a brand A car (the luxury division of brand H) with a 4-cylinder overhead-cam coil-on-plug engine, similar to a Gen1 Prius, with 250,000+ miles. They've had two coils fail. One other problem they've had is that the plastic shell of the low-voltage connector on the harness side seems to break down with heat and time; if you try to unplug it from the coil, the plastic shatters. Replacement connectors with a wire pigtail are readily available aftermarket; they've replaced 2 of the 4 connectors on their engine. So it might be an idea to at least look over the low-voltage connectors with a strong light.

Trivia:

The plugs that came with my 2001 from the factory were NGK IFR5A11. Having driven mostly 70s and 80s Detroit cars before the Prius, I didn't know a spark plug could last more than about 30,000 miles. When the Prius hit around 75,000 miles, I decided to look at the plugs on oil-change day... and they were fine. The gap was in spec. There was a little bit of deposit on the ceramic insulator - it wasn't pristine white like a brand-new plug - but it didn't look like anything that would cause a misfire. I put them back in and ran them until 137,000 miles in 2011, when I finally changed them. I changed them again at 237,000 miles in 2022.

NGK had some literature in 2011 that stated that the IFR5T11 was the aftermarket version of the IFR5A11, so I bought four of the IFR5T11s plugs. As I recall, the replacement 5T11s were mechanically identical to the factory 5A11 plugs. The 2011 set was made in Japan, while the 2022 set was made in Thailand.

The spark plug boxes tell you not to bend the ground electrode to adjust the gap (or maybe they don't want you to pry between hot and ground to adjust the gap), but I always check the gap with a blade-type feeler gauge anyway before I install them. Factory spec is "1.0-1.1 mm STD, 1.2 mm maximum", or 0.039-0.043 in STD, 0.047 in maximum.

One thing I do, that's not in the factory manual, is to put a little bit of copper anti-seize grease on the plug threads before installing. I try to keep it up towards the gasket/seat and away from the electrodes. My theory is that since they're going to be in there for 100,000 miles, I really don't want the steel plug threads to seize in the aluminum head. In theory, the grease changes the torque wrench setting, but in practice, I torque them to the factory spec (18 newton-meters, 13 foot-pounds force) and they seem to do OK.

 

OP (Tryyn) has a 2002, so he/she should use the Denso SK16R11 Iridium 3324 plugs.

 

While you can certainly find spark plugs online for less money, and you can even find ones that claim to be the OEM specified plugs and come in very-well-copied Denso packaging, you have to be extremely careful, because counterfeiting is rampant, and huge in spark plugs, and if a bogus spark plug frags electrode or ceramic bits into your cylinder, the money you saved on the spark plug pales to insignificance.

Plugs are one thing I will probably never buy except from the brick-and-mortar job shop here in town.

 

Understood. Advance Auto is currently selling the SK16R11 plugs for $8.63 apiece (Advance Auto Parts - Down for Maintenance).

 

Great success!

According to the wiring diagram, both fans should be running at the same speed. There are two possible speeds. "Low" is both fans in series (so they each get roughly 7 V) and "high" is both fans in parallel (so they each get roughly 14 V).

The decision to start "low" speed is made by a water temperature switch; it turns on "Fan No. 3 Relay". The decision to switch to "high" speed is made by the "A/C Single Pressure Switch"; it turns on both "Fan No. 1 Relay" and "Fan No. 2 Relay". All of these relays are in the box on the passenger side inner fender.