Oxygen Sensor questions

[RyDeFly]

My 1988 Turbo failed emmisions (5 times higher than what it should have been) and the mechanic I took it to said that the oxygen sensor needs to be replaced, which he can do for $315. o_O
The Toyota dealership can get the part and install it for $240...
I was under the impression that O2 sensors were like $40....

My question is, do I HAVE to use a special 1988 supra sensor, or can I buy a generic sensor? Where is it located in the car, and can I replace it easily myself?

The mechanic also said that the inside of the intake manifold has heavy carbon deposits, and they can clean it out for $170.....reasonable or not?

Thanks guys.

[kewlcoconut]

omg do NOT go to your mechanic or the dealership. they are ripping you off by over $200. you can EASILY do this yourself.

you just need an O2 sensor for an 88 turbo. the turbo and NA supras are different. the turbos have a 3 wire sensor and the NA has a 1 wire. make sure you get the 3 wire replacement. from what i know, the Denso 02 sensor is the 3 wire one and the Bosch one is 1 wire. they run for about $50 or so. And it will take you about 5 mins to put in.

just look under the hood on the passenger side. In my NA the o2 sensor is on the headers. on the turbo models i believe the o2 sensor is on the downpipe. but still reachable from the passenger side by the intake.

this will take you 5 mins.....super easy.

go to your local auto place, and try and look for a carbon cleaner to spray into the intake. i think there is a product i heard some people talking about a while ago called seafoam? im not quite sure.

but seriously, do not go to your mechanic or dealership for the o2 sensor. you can save over $200.

[j3pz]

out of curiosity, how do they know you got carbon buildup in the intake? and yes you would get ripped off 200$ for this

[Isphius]

How would carbon even get into the intake? unless you car backfires everyday. I went to meinike to get a 4 wheel alignment and they told me i needed new wheel bearings on all 4 wheels. 75$ each for labor and 60$ each for the bearings and grease seals. so i basically gave them the finger and never went back there. I went to a local shop around my house and they charged me 60$ for the 4 wheel alignment and now its fine. lol. The only reason i did this was because my rear wheel was misaligned, one of the arms was out of adjustment. I would also say just buy the oxygen sensor...i changed it myself in 10 minutes, and i have mechanical experience but never changed an o2 sensor. Just unplug and unbolt the old one, change the plug to the new one, shrink wrap the connection, and bolt it back on. my car actually seems to have a little more power and run a little smoother right through 2500~~3500.

[RyDeFly]

I was mistaken, there was no carbon in the intake....

Mechanic wanted to clean out the fuel line because of the large amount of carbon deposits from the Supra running extremely rich from the bad o2 sensor. Is this also something I could do?

>>the Denso 02 sensor is the 3 wire one
I'm assuming Denso is aftermarket, or least not OEM, right? Where can I get those? The actual Toyota oem part is $154 and I have to order it.

>>Just unplug and unbolt the old one, change the plug to the new one, shrink wrap the connection, and bolt it back on.
How do I shrink wrap a connection? Does it involve actual shrink WRAP? Heh, sorry I've never heard of that before.

Mechanics also said that the Turbo hose is loose i.e. not connected....I was under the impression that the turbo had PIPES, not hoses..

My throttle linkage assembly is messed up, and my car idles at 2500rpm, anybody have any experience replacing one of those?

[mrnickleye]

Trust me (see my profile), you can get an aftermarket 3-wire 02 for about $75. Bosch is the most popular at the parts houses. You can get one with the oem plug already on to just plug-n-play.

You may want to spray some WD40 (or similar) on the threads a few times and hours before removing it.

If your mech. said fuel 'lines', (carboned up) get a new mechanic, he IS ripping you off, cause that just won't happen. Also, we only charge $65 labor to replace the 02. (and we also re-check everything to make sure you are gonna pass the test).

It is very true that carbon builds up on the inside of the intake manifold. This is due MOSTLY from the EGR system feeding exhaust gasses into the manifold. It also builds up on the intake valves.

Maybe he meant that the carbon is built up in the egr passages, and therefore the egr system is not working, and will cause the NOx to be too high.

I would ask around (friends, family, co-workers, grocery store clerks, etc) for a recommended shop to check out your car, and make some of the repairs if you can't. Cleaning the egr passages is work, but easy, but does take some mechanical skill, and knowing what to remove and clean.

If you idle is high, you WILL fail the test. That sounds like other issues. How do you drive with that??

[RyDeFly]

Like I said, the throttle is jacked up; its the assembly that runs along top of the engine near the firewall. The thing is way loose, so the cable is not retracted all the way, making the idle 2000-2500. I can pull it back with my hand and the idle will drop.

Once I engage the clutch, the rpms drop back down to what it should be, so driving it is not that hard... probably just stresful on the clutch though.

I'm pretty sure the mechanic said "fuel line", and he refered to "flushing it out" because of carbon deposits from it running rich for so long. BS then?

Also, maybe the "turbo hose" he was talking about is a vacuum line?

Thanks for you help guys.

[kewlcoconut]

dammit. i just spent like 5 mins writing a response to all your questions and browser somehow jumped back to the main page....so here it is in short

Google the o2 sensor for the supra. or visit stores you know. you can get it for under $100 easily. I heard Bosch isnt that great, people say they crap out pretty easily. Although that is just speculation. The Denso sensors can be different. you can get ones with the connectors, or with just the wire to connect to the old sensor wire. and here is a link on how to heat shrink all that stuff.

http://photos.dylanwiggins.com/thumbnails.php?album=146

as for your fuel line, do you ever use fuel injector cleaner? it does wonders if you use it. I make it a habit to use it every 1500kms or so. just to keep my fuel system good.

[mrnickleye]

perhaps the mechanic meant the fuel injectors were carboned up. This can be a common problem. Do as mentioned above, and use fuel injection cleaner in the fuel tank to clean out 'varnish' in everything, and carbon on the tips of the injectors.
Dirty injectors can stick open, and/or spray in a crappy pattern, which can cause engine running problems.

[kewlcoconut]

I highly suggest buying a new o2 sensor. I JUST replaced mine today. And took some pics of the old one. It's horrible looking.........change yours!!