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Hey all , so first civic here just got givin to me due to granparents knee surgery and cant clutch anymore. but here it is.

98 hx , 170,000 + miles with no known history yet. waiting to get details but gona treat as a moderate maintained ride. will be going thru in near future.

so yes cel is on and was told it has been on since 60,000 miles and still driven.
code is for pre cat 02 sensor ( yes the 400 dollar one) due to manual trans.

so warmed her up and then blipped the gas to roughly 2000 rpm and when let off the tach dropped to almost zero and car almost stalled (rattled a little) then kicked back up to normal idle. did this several times and same result.

took off iacv and was full. screen was blocked almost completly . cleaned until looked new. started car let warm up then tried again at tb and still same result. plugs are new as is fuel filter. haven"t checked distrib yet.wires look good but i know looks don"t meen anything.

any advice please /more details needed can provide what is known to me .
thanx in advance.

 
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jus lil update. pulled the distrib cover , was little build up on tips and some corrosion . cleaned off what could with out damaging anything. no improvement. checked air filter , new. gona check pcv next and pull plugs to look at.

plan on getting the pre cat 02sensor replaced to clear cel.

should i do a seafoam treatment to see if can clear out cat a little does anyone think?

 
Rep Power: 519

I'd say to fix the O2 sensor (LAF sensor?) first since your complaint could easily be caused by a fuel control issue. (Use only OE brand sensors, I assume it's a DENSO. Check the DENSO website too.)

Then clean the throttle body.
And inspect for a "base idle adjustment" if necessary.

Then let the engine do an idle relearn.

Then see what happens.

 
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thanx. yeah thats my plan . also to reg the car i have to emmision test so will need to do. sux thing is 400 bucks but got car for free so cant say it would be bad to do.lol. was also told car smoked for while (sooty blk) so guessing thats the carbon build up issue. plan on pulling whole intake manif off and givin a blast of cleaner thru it all so will get TB at that time. thanx again and if any update soon ill post it.