98 Buick lesabre,p0420 code, o2 sensors?cat?

[ziggy]

I see!.I kinda figured,something in me told me,a feeling, boot a good idea. .
Ok I will try that. I did but a bottle of k&w head gasket and radiator sealer,orange bottle, you pour it in and drive. Thought perhaps after a few more days, maybe the block itself might be cracked...
I used a a.c. Delco torque adapter.I do know in 3 bolts the readings had read about 202 inch lbs,not 190, because I had too use the adapter in reverse order.normal would be ratchet, extension,afaptet,3/8 bit. Because the adapter was too big too fit in,I did ratchet,adapter,extension,3/8 bit. I noted it gave a diffetent torque,feeling. So wanted too check without loosening the manifold bolts first, the exact torque,with a bow type torque wrench.

 

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Perhaps bad 02 sensors causing the code? Cat inefficient somethinganother...car has 111,500 j le s in it.they most likely have never been replaced.

 

[Lubener]

Originally Posted By: ziggy
Perhaps bad 02 sensors causing the code? Cat inefficient somethinganother...car has 111,500 j le s in it.they most likely have never been replaced.

If enough coolant was being burned, it could have damaged the Cat and or the O2 sensors.The Cat should just about last the life of the vehicle under ideal conditions. It most often fails as a result of another significant problem.

 

[ziggy]

Of it was the 02 sensors, would I get a p0402 code?or a different code?

 

[Merkava_4]

Originally Posted By: ziggy
I let the rt v dry like 48 hours.perhaps the rubber on the gadket,didn't seat into the square holes on the intake manifold? Perhaps the plastic side bars under it? I put rt v on the ends,generiously,on all four corners.


All those gaskets have locating pins. I you didn't put them in the correct location, you would've known immediately.

 

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Well! What a day! I took the plenum off, left the intake on...loosened all 12 volts slightly,just slighty. Used a bow torque too re tighten 15 ft.lbs. Give or take. Put plenum back on.it leaked,from thermostat housing intake manifold area. The cause..in the bottom plenum,theirs 2 blue rubber gaskets, which fit over 2 holes on lower intake.poured coolant in,and verified th is a 2 holes are where it was from,the leak. The rubber gromet gasket had fallen off,not in good shaoe.theirs 2 of them, and new felpro kit didn't come with new ones,just 2 Orange o rings. Found the old one,blue hornet ring,put it into plenum hole. Used the a.c. Delco adapter torque cube, verified 2 times, 190/191 inch lbs. All 12 bolts. Used it too tighten 10 volts on plenum, 89/90 inch lbs.
Coolant leak stopped. Put new a.c. Delco plugs in today. Left a hose off a small egr circular thing near intake part of pl enum. Car smoked like crazy!!! Found it, put the tiny hose back in.stopped smoking.ga be off a semi deafening win d noise near air box and mass airflow. Noise went away. And that's with a flaslight!!! Not bad! Should been done hours ago,had i used the old blue grommet in bad condition,and probably the DElco torque cube.

 

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No check engine light was on,when I finished,let car run for 15/20 minutes.no cell went off. Hoping it stays this way. Coolant had run all over the top of lower intake ,when I retook plenum off.quote a non fun cleanup job.

 

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Do they sell those blue rubber former gasket things? Or would i have too but a new pl enum? The help to kit did come with t hem.theirs 2 of them , right hand side inbetween the plenum gas ket.they go over 2 holes that are in the lower intake.

 

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Check engine light came r back on after half hour of driving.got home,one reader said same t hing...p 0402 catalyc converter insufficient bank 1. I'm wondering,on right side of plenum,near mass air flow, inbetween the top plenum and too of intake manifolkd, are thie r supposed too be 1 or 2 blue silicone or rubber gaskets or something,that go over 2 holes inbetween the bottom of plenum and manifold? Bypass valve gaskets? I hadn't checked,but am expecting too find,my coolant level down.
I didn't replace the entire upper plenum,just a new gadke t with new pope in it.I read,these plenum distort. Perhaps replace that?
The original, had a blue o ring robbed looking flatish gasket inbetween a hole, between manifold ,plenum gsdket. The fe l pro gas ket u got for upper came with a longer thinner version of it.it for into a small hole, thier 2 on manifold, but out the old semi melted one back in,as it made the manifold plenum not leak.I have no idea what the thinner longer robbed blue gasket, bypass grommet looking thing is for.

 

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Ok so basicaly, I got the gel pro 98014 gasket set. Theirs a little blue rubber former plug looking thing...where does that go?
It came with 2 Orange o rings,what are those for?
I'm thinking,the help to kit didn't come with complete ring gaskets that go between pkenum.plenum.
Theirs some holes in the intake top, the plenum gasket covers. Sent the new gaskets,supposed too come with gaskets installed in? Or no?

 

[Merkava_4]

Ziggy: The blue plug is a new seal for the MAP sensor, and the orange o-rings are extra o-rings for the coolant elbow that goes into the lower intake manifold.

 

[ziggy]

Ah ok! The doorman elbow i installed, already had o rings on them.
Well,the car ran fine, but tonight,leaving work, thie r was a weird metal scarfing sound,sounded like it was coming from under car, cat area.it's been doing this since I bought it,and before this intake gasket issue. The noise is thier on startup,for a few seconds. Tonight,the cell came back on. I already re did the intake bolts, the cell went off,meaning the light was off. Put maybe 100 miles on it,and tonight,the weird metal scrafing noise,and the cell popped on.
I have had too add some coolant,but like an ounce. I'm gonna try some me radiator and engine sealer. I did note...when I re did the g lts...the side liners under the manifold,thie t blue.one seems to be just slightly visible,outside the lower intake. Should that matter?it's just ever so slight...
I'm feeling the cat is shot....

 

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It has 111,600 miles.I'm assuming number one,the o2 sensors should be replaced? Perhaps that's what causing the scarfing noise from cat area,in startup.??? Or the cat is shot or both.?

 

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Looking at YouTube vids,regarding the upper intake...maybe I should replace it.I'm looking at ATP or doorman. Which would be best?
Are thie r any gaskets that go into any of the upper plenum gasket holes? Not obviouysly,the holes that come with new gasket,but is thie r supposed to be a gasket that goes into the holkes?the ones in the thermostat side of plenum and g asket? Mine appeared too have had a rubber one badly melted looking.

 

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Did some reading on amazon, and one guy was saying, atp...he looked it. If your looking coolant and have no visible evidence of leaking coolant ( my problem) then replace the plenium,which I didnt.
All I need,is the gasket as well.outside of the provided gasket for plkenium,are thie r any other gaskets i need too install,into the ring gaskets,on the new p Lenin gasket? Or its just install as is?

 

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I think theirs 2 rubber gaskets or whatever,that go into 2 holes bottom of to o p lenum. One had broken off,look us melted.i can't see in pictures,if new too plenum comes with those or not. On any website. They got into 2 large holes,of new gaskets. I left the broken off one out,it leaked bad. Put it back o n.hoping the torque would hold it..it did good close too a week. It's a 2nd hand car,that had less than half a thermostat in it.so looking for as much info as I can...so it's fixed.

 

[Lubener]

After reading, this repair should have been done by a qualified technician. It was beyond your skill level. Nothing to be ashamed of. The upper plenum was junk from the begining. Prone to warpage and burn thru. You didn't take the advice given long ago, to replace it when taking on this project.I hope you found all the pieces of the thermostat. With Winter coming, I hope you have a warm garage to work in and please do not put stop leak in the cooling system.

 

[mk378]

Do not use stop leak. Just don't.

 

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Ok I wont. Yes it was a new skill. But have taken it apart so many times, I'm kinda a pro at that part.I'm gonna order a new plenum. Atl in thinking.
My question is, the bottom of the plkenum...are thie r supposed to be 2 rubber plug type gaskets in them? My old one,appears it did. If the new didn't come with them,can I get new plug ,type water passage plugs? They had a hole in them,for between the 2 large plenum gasket itself,holes.
Any of the aftermarket plkenums,with gasket,kit,are ready too install. Nothing additional. Correct!

 

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So..in that note. Atp or Dorman plenum..which should I get?