Hey i'm having some trouble with my 1989 Civic Lx auto a little background on the car it has 87,958 original miles bought it last year from a 93 year old woman and i know for a fact she only put 11,000 miles on it from '04-'14 so it did sit a lot. Now for the problems whenever I'm driving say up a steep hill or if i just driving for a while car has this burnt match sulfur type exhaust smell it seems to be originating from the front of the car but i cant tell i can only smell it from inside the car or when i first park and get out it dissipates really fast. Next every cold start is around 1250-1500 rpms then drops to bout 1k to 750 as soon as i shift into gear also sometimes when i put the car in reverse or into drive the rpms drop to around 300-400 the car never stalls but it runs shitty for a bit until i give it gas. This usually happens after the car has gotten up to temp say if i go to the store then come back and start the car again also happens sometimes when i come to a stop at a redlight. All of these problems are intermittent and are driving me insane. Here is a list of things i did to try and fix it but nothing helped.
- New catalytic converter
- New o2 sensor
- Full cat-back exhaust
- New Iacv valve
- Cleaned Egr valve and replaced gasket
- New Fuel filter
- Radiator flush
- Transmission flush

All of this was done in past week or two.
When i bought the car last year at 85,000 i replaced
- Plugs
- Wires
- Cap and rotor
- Oil filter and oil change

I don't know what else to do my mechanic said he doesn't know old hondas that well and there aren't any good independent honda shops in my area any help would be appreciated and i guess my last resort is going to a honda dealership but idk if they will be able to help.
Thanks!

 

Have you tried changing your flux capacitor? My old friend Emmet "Doc" Brown did it for his apprentice Marty McFly's DeLeorean. It had similar issues. Hope this helps!

 

How many miles have you put on it?

 

Almost 3000 miles

Also today I shifted from drive into reverse and rpms spiked from 1000 to 1500 real fast and then back down idk wtf is wrong with my car

 

Is it an automatic?

 

Yea

 

I have officially stumped honda tech

 

Poor idle, sluggish throttle response and the teltel sulfer smell are all signs of clogged cat converter..did u have it replaced or did pre owner say it had been replaced?

 

I had it replaced

 

Do you have pressure on all the cylinders?

How is your throttle body?

 

Well i replaced the iac valve i put on with the old one i had i guess it turns out the one i put on was actually bad so the idle hunting stopped but the idle still drops low and the sulfur smell is still around. As for the pressure on all cylinders idk how to check that and i dont think im that mechanically inclined, for the throttle body i cleaned it with carb cleaner and a tooth brush getting rid of all the dirt and gunk so i dont think its that. When its warmed up and moving i dont have power loss issues and it doesnt seem sluggish when driving the idle drops when i comek to a red light or when i turn the car on after having just used it or cold starting it also it doesnt happen all the time usually when shifting into gear from park or neutral.