TheBoiKing

I've been replacing things on my 1986 C&C for years as a project due to age, wear and tear, and a whole lot of poor care by POs and when I went to replace the O2 sensor today - it didn't fit. Arg. The new sensor is an OE Denso (part #: 234-1056) that when inserted into the exhaust manifold wont go more than an 1/8" onto the bolts. It seems like the actual sensor is hitting something inside the manifold but there's nothing I can feel that would be in the way and it should go in at least as far as the old sensor did (Bosch). I can insert my finger in far enough that the O2 sensor should be just fine, but it's not. Everything lines up enough and isn't catching from the outside. Now my next step is to separate the exhaust manifold from the rest of the exhaust at that attachment point but before I start messing with things I wanted to reach out. This *should* be plug-n-play. Any ideas?

moto809

Only easy solution I can think of is carbon buildup. Maybe a quick scrape will make it fit...
Otherwise, wrong part.
I don't see what else could cause that.

TheBoiKing

Moto809, I'm nearly 100% sure it's the correct sensor so I'm just going to take it apart. Thanks anyway.

2ToyGuy

Could it be that the Bosch part spread the bolts just a leetle bit? Did you maybe try inserting the new one into the hole (I'm NOT going there...) turned so that it's 90° out? IE sideways, so the flange is between the bolts, not ON the bolts, to see if it's a problem with the hole, or is it a problem with the bolts? Did you try fitting it on just one bolt, to see if the bolts are just a hair too big for the holes in the flange?
If that were the problem, just in case it is, could you maybe drill out the holes just a hair bigger, to make it fit?

Just my few little thoughts. I get so few of them any more...
Pat☺

Jimkola

I had the same issue. Is your vehicle CA? I was guessing that the Denso O2 was for 49 states to why I was having a fitment issue. I tried a different Denso sensor part # but had the same problem.

TheBoiKing

Jimkola, it's not a CA vehicle, thankfully. If I had more stuff to deal with fixing I may have lit the truck on fire by now. What was your eventual solution? The new Denso sensor is clearly more hardy past the flange than the Bosch sensor, but not if I can't install it.

TheBoiKing

2ToyGuy, I, too, was wondering about the sensor flange catching on the bolts and it doesn't seem that way but I'm going to look a bit closer and more slowly this weekend. I also did try turning the sensor 90 degrees hoping for more input and it just catches on the manifold itself. I also tried rotating it 180 degrees and that didn't work either. I'll try your last point and see if one hole on the flange will fit all the way down on one bolt. Thanks for the input. By the way, I lived in Tucson for a long while.

Jimkola

It’s been awhile since I attempted to replace, but the OEM sensor in my vehicle was clearly different than the Denso replacement.
fortunately, my existing sensor was ok,I was just replacing because the Denso replacement was so inexpensive.

Co_94_PU

iTrader: (-1)

234-1056 fits my flange with no issues, I'm not aware of there being any difference in the exhaust manifolds for fed vs Cali emissions.

Off hand I recall the bosh has a separate flange that's required to attach it, where the denso comes with it preattached.

Co_94_PU

iTrader: (-1)

Thread with pictures..

Can see the Bosch is shorter, thinner, but seems to have the same flange.

Fwiw

Jimkola

The flange and stud spacing/diameter wasn’t the issue in my case. I simply couldn’t get the probe all the way into manifold. I had the manifold out at one point and I recall that I could clearly see a casting issue, but it’s been over a year and the exact issue eludes me.

2ToyGuy

Sorry I wasn't more help. As a mechanic, I make a darn good radar tech.

My condolances on living in Tuscon. I got stationed in Yuma, at the Marine base, on Jan 1, 1980. I hated the place for nearly 30 years after that. I stayed because I got a very good job when I got out with the Aerostat program. I also had 3 kids by then, and I had bought some property. 2 more kids after that. It was better, in my pea brain, to stay in place than pack everything, and everyone, up and move them all. IMHO, it's better to let kids live where they are born, until they're out and on their own. It gives them a base to build their lives on. In my opinion.
Besides, have YOU ever tried to move a household, and 5 kids, any distance?? Not only expensive, but young children don't do well in a vehicle for any length of time...
As soon as the kids were grown and gone, though, I was out of there. By then, I was medically retired from work, and some of the kids went into the service after me. I will never go anywhere near Yuma again. I could go through my usual rant about just what I hate about Yuma, but I'll spare you all my whining.

Good luck with your O2 sensor!
Pat☺

arlindsay1992

iTrader: (8)

When I bought my truck it had a generic O2 sensor installed. It eventually needed to be replaced and I bought a genuine Denso replacement. The generic one had a smaller diameter sensor tip. Carbon had built up around it and wouldn't allow the Denso one to fit. I had to clean the carbon build up with a Dremel. Didn't take long and fixed the problem right up.

DavidCharles

Check the sensor diameter vs the manifold hole diameter. The sensor could have a stepped casing that is too large diameter for the manifold hole. I've replace several O2 Sensors with Denso units in my 86 truck with a 22re and they all fit. Denso narrow band (# 234-1056) w/gasket. Truck runs and idles smoothly.

TheBoiKing

Hey Pat, I'm just seeing your reply. Apologies for the time delay. I don't have kids but moving 5 of 'em any distance does not sound like a good time to me at all - I don't need to have kids to know that I know that for sure. That having been said Yuma and Tucson are pretty different and if I'd lived in Yuma well, I wouldn't have lasted nearly as long! I've got a friend that I brew beer with that grew up in Yuma...he has no plans of ever moving back. lol.
Thanks for suggestions re. the O2 sensor. I finally got it.

TheBoiKing

Hey Pat, I'm just seeing your reply. Apologies for the time delay. I don't have kids but moving 5 of 'em any distance does not sound like a good time to me - I don't need to have kids to know that I know that for sure. That having been said, Yuma and Tucson are pretty different and if I'd lived in Yuma well, it wouldn't have been for very long! I don't blame you. I've got a good friend that I brew beer with who grew up in Yuma...he has no plans of ever moving back. lol. Thanks for the suggestions re. the O2 sensor. I finally got it.

TheBoiKing

Thanks for the insight! I ended up letting the truck sit for a few days without a sensor installed then went out and sanded the surface a bit a couple of times. I think the previous sensor put a slightly amount of tension on the bolts and the carbon build up added to the problem. It took a few tries but I was able to get the new sensor installed. Success!