2015.08.24

Mitsubishi 3000GT VR4 turbo engine bay strut brace suspension
O2 sensor

The VR4 was throwing a check engine light. After paying $95 for a "diagnostic code check" on the Tacoma in conjunction with a smog check, I decided it was time to get an OBD reader. $23.49 + $6.99 cord and the free version of the Torque app later, I get:

Torque app OBD reader fault code screenshot

Cool, a malfunctioning O2 sensor heater is a pretty sure bet that replacing the sensor will fix the problem. Bank 2 sensor 1 though? The 3si forums pointed me to the upstream (of the cat) sensor on the left (rear) side of the block.

Mitsubishi 3000GT VR4 turbo oxygen sensor 14925 replacement

Source.

And there it was, but could I reach it? Stealth316 seemed to believe I could. Great. $30.29 for a sensor, #13801, that Amazon and Bosch assured me would fit "upstream left".

Mitsubishi 3000GT VR4 turbo oxygen sensor strut brace

The space around the sensor is pretty tight, but it's reachable by removing a few pipes/hoses/cables. Getting the sensor out, however, was not easy. The first socket I bought only contacted the sensor on five sides, since it needs to get around the wire. This one actually bit into and partially rounded off the sensor. I bought a different socket that offsets the wrench attachment, this one eventually broke the sensor free.

Mitsubishi 3000GT VR4 turbo faulty oxygen sensor part

Installation was almost seemless. As it turns out, the wires were not long enough to reach the harness, so I had to splice. Bleh. Thanks Bosch.

Tacoma (shop): $95 odb scan (and hopefully some labor) + $85 sensor + $125 = $315.
VR4 (me): $30 scanner + $30 sensor + $15 sockets = $75.

The other upstream sensor looks like a total pain to access, but the downstream ones seem accessible from under the car.
Suspension research

Since the VR4's springs and struts were going on twenty years without replacement, I decided to replace them.


There isn't much out there, Tire Rack and Amazon both indicated the only way to go was KYB GR-2s and H&R springs. Cool, GR-2s and Eibachs worked very well on the Celica. I did find a few coilover kits ranging from $900-$2000, but was worried about fitment, ride quality, and longevity.

Again, Stealth 316 was a great resource.
Rears

Mitsubishi 3000GT VR4 turbo KYB strut boot shock

I started with the rears, since they attach to the suspension with a single bolt. Unfortunately, that bolt was robustly seized. S316 suggested using a gear puller, which I did not have. Since it was too late in the evening to buy one, I moved to the fronts.
Front removal


These had a few more bolts and two lines (brake and abs?) that attach to the strut. It was a bit tricky to keep the assembly from dropping onto the cv boot, but not too much of a problem.
Front disassembly


Getting the top nut off can be a pain, but I managed using a pipe wrench to brace the lower section.
Front assembly

Mitsubishi 3000GT VR4 turbo strut spring HR KYB replacement

The strut/spring combination went together as usual: strut, bumpstop/boot, spring, upper spring seat (reused), mount plate, top nut. I used an impact wrench, gingerly, on the top nut.

Front install

Snaking the strut tower back into position required just the right movement, but it worked out. Then it was just a matter of threadlocking and tightening everything.

Rears again, removal and disassembly

Mitsubishi 3000GT VR4 turbo jack strut spring rear brake

I went to the auto parts store and bought an $8, two-pronged gear puller. The arms promptly bent. I went back to the auto parts store and bought a $17 gear puller with three beefier arms (seen above). It was challenging to simultaneously tighten it and hold the arms in place, but eventually it did the job.
Rear disassembly

Mitsubishi 3000GT VR4 turbo rear strut spring replacement KYB

The thing came apart without challenge, but here I noticed the strut rod on the KYB was larger diameter than stock. This is good, right? More strength.
Rear assembly

Mitsubishi 3000GT VR4 turbo suspension KYB mount plate strut mismatch

The wider strut rod seemed to be okay since the rubber bushings fit it perfectly, whereas they used a metal collar to adapt to the OEM struts. But I wanted to make sure I assembled the thing correctly, so I emailed KYB:

Hi, I'm installing struts and springs (H&R 52981) on a:
1997 Mitsubishi 3000GT VR4/AWD/Non-ECS

Using the following parts:
- Front strut 335013
- Front strut mount SM5096
- Front strut boot SB101
- Rear strut 341185
- Rear strut mount SM5091
- Rear strut boot SB108

Your application guide, Tirerack's, and Amazon's all seemed to agree that these are the correct parts. The fronts went on perfectly, but I am not sure how to proceed with the rears.

The mount and boot kits do not appear to match up with the strut.

- The inner diameter of the washer supplied with the bump stop is smaller than the outer diameter of the strut rod.
- The same diameter issue exists with the collar.
- All of the rubber pieces fit, the strut rod fits through the mount plate with enough space (axially) for the rubber bushing.

The apparatus actually can be assembled to fit in the car, however without the correct-size washer or collar, the mount plate is just sandwiched between bushings, which is disconcerting.

So, if there is another mount kit that better matches the strut, I guess I need to get that. Alternatively, if you can advise me on specifically how I should assemble it, I can get whatever washers/collars I am missing from McMaster-Carr.

Thank you for your help.

Their response was as lengthy as it was helpful.

Chris,

Sorry, that strut will not fit the rear of your 300GT. The 341185 is for converting from electronic. We donít carry a strut to fit the non-ECS VR4.

Mitsubishi 3000GT VR4 turbo KYB suspension catalog

Gee, their only parts are unmatched struts and mounts. And you'd think adapting an ECS assembly to non-ECS would have some overlap with non-ECS originals. Between the fitment issue (remember Tire Rack and Amazon were under the same impression) and the terse, unhelpful response, no more KYB products for me.

Well, the only difference between the old and new struts was a metal collar that lets the rubber bushing fit the thinner strut rod. So I picked up some washers and put it together: strut, bumpstop/boot, washer, wider washer, bushing, mount plate, bushing, washer, lock washer, top nut.

Mitsubishi 3000GT VR4 turbo rear strut spring replacement KYB HR
Rear install


As KYB stresses everywhere except their installation manual, don't tighten the top nut until the vehicle is on the ground.
Assessment

The fronts are great and I am keeping an eye on the rears. There is some light metal-on-metal contact, either: