[flashover]

I have a 2005 Kia Rio with 170,000mi. that I just picked up with these problems. Car starts up fine but idles rough and it sounds like it might have an exhaust leak. When I try to accelerate the car boggs out and will only accelerate very slow and and it almost feels like it is going to stall. Eventually the car will get up to about 65 as long as I am on a flat road. If I hit a hill the car will down shift and rev up to 3500-4000 RPM and no power. If I back off the car will downshift and maintain power speed again as long as I stay on a flat road. Motor seems to run smooth unless it is under a load. The timing belt has been replaced about 30,000mi ago. Plug wires are new but I dont know about the plugs. Previous owner said that he swapped out the could packs but put the old ones back on when the problem wasn't fixed. Dont know if fuel filter has been done. Both cams line up with top marks. I should also point out that the exhaust smells a little rich.
Also, The Dim headlights don't work and brights do but only when I pull on the headlight switch, nothing happens when I push it forward. All fuses are good but the head relay is gone, I swapped it with the horn relay and still nothing, and the filaments in both bulbs look good (actually new).
Codes:
P0507 - IAC System
P0170 - Fuel trim bank 1 - too rich or lean
P300 301 302 303 304 - Misfire generic and all cylinders

Can anybody help. I would like to test the injectors without replacing them, I was going to try to unplug them one at a time to see if the idle cleans up like I did on my camaro. But, I cant pull the plug off because it is so close to the valve cover. I am thinking injectors are needed but I thats just my guess from the symptoms

 

[jcwit]

What are the plugs? What is the gap?

RIO's like OEM plugs "NGK" and a gap between .028 to .032.

 

[DavesSpectra]

With 170k miles on the car I'd check the Catalytic Converters...Sounds like they are plugged...Slow acceleration, down shifting and no power, misfires..
If you can get a real time scan tool (OBDII) and look at the O2 sensors (upstream and down) if the downstream matches the upstream voltages...the first cat is gone...
Also if you can get a reading at the "bung hole" the upstream O2 sensor is screwed into the back pressure should be below 2~3 psi...Above that and the cats are plugged.

Headlights...
Wire colors =(x/x)
IG2 fuse 30A (B/L) to ign switch, from ign switch (L/B) to RELAY fuse10A, from RELAY fuse (R) to coil headlight relay, from coil headlight relay (L) to main fuse box (under hood), from main fuse box(L) to headlight switch on steering column. this turns on both high and low headlights (provides basic power).

Lowbeams...
from HEAD fuse 25A (L/B) to common contact headlight relay. from n/o contact on headlight relay (G/R) to headlight switch on steering column, from headlight switch (R) to main fuse box (under hood), from main fuse box (Y/R) to headlight bulbs (low beams), from bulbs to body/ground.

Hope this helps...
Dave

 

[flashover]

Thank you Dave and jcwit. I will try all of that in a couple of days. If anyone else has any ideas or has had the same issue please share. I need to get this car running reliably as soon as possible. Thanks

 

[ronjohn]

I aggree with dave on the blocked cat's an easy way to check is to disconnect the second cat pipe The one between the two cats and see if that helps it will be loud thoe, if it does the second cat is blocked if it doesn't it would be the first hopefully not very expensive part. The second was my issue same symtoms P0300-po304. could not get up a little hill but going level or down the car would go alot faster poor idle and whatnot. If you can clean the throttle body and IAC valve that will help and should be done anyway now that it is all carboned up. You have to remove the valve to clean it good, search the post here me and kevster have a good write up on numerous post's. I knocked my second cat out and the car runs good now it came back to life immediaitly after i did it (Thank's Dave) As far as the headlights i would look at why the headlight relay is not working if the pass function works the 25 head fuse is ok maybe the combonation switch is bad good luck and keep at it you will get it fixed and keep us informed everyone is here to help. Oh i did not see it here but http://www.kiatechinfo.com/ for service materials free from Kia just have to register schematics and everything. I hope this helps. Reguards Ronjohn

 

[flashover]

Thanks, I will check the exhaust back pressure. I understand that the upper O2 sensor hole will indicate a bad upper cat. Will the bunghole for the second O2 sensor do the same for the second cat? Also, just to be sure that the last guy didn't mix up the plug wires, The cylinders are 1234 from passenger side to driver side correct? I just want to be sure that everything is where it should be before I chase the bigger possibilities. One more thing, is there a way to test the injectors if it is not the Cat's? By the way, where is the combination switch, or is that the switch on the column?

 

[flashover]

I don't know I you got my reply. I tested the back pressure and it was at less than 1psi. I am going to check the plug gaps, clean the TB and IAC , is there anything I should be carefully with? Also, what next if none of this works. Thanks

 

[Kevster]

Did you test the pressure at full throttle? It will read low at idle but may rise rapidly as the car is revved. Under actual load this pressure is even greater, hence the "less than 2 psi" recommendation. I had a 2004 that had a bad first catalyst, and the pressure seemed good and low until you revved it and held it at 3000-3500rpm where it rapidly rose up to 8-9 psi if I recall correctly. Once replaced, it NEVER exceeded 3 psi no matter what it was revved to.
Since the O2 sensors control the fuel, I would replace them (especially the first) if they seem old (the last owner may have done them already). The first is the fuel metering control, and the second is mostly a function test to see if there is a catalytic reaction taking place.
I would look at intake leaks as well. I had a tiny one at my intake manifold and it threw misfire codes and MAF sensor codes and lean and rich codes. Finally, make sure the IACV is clean and not leaking( aw heck I would replace THAT thing first!)....as that darn gadget caused me(and the dealership) no end of confusion. My bad IACV had the tech at Kia changing the O2 sensors (which were new), Reprogramming the ECU, and recommending I replace things I had already replaced (like the MAF sensor and Throttle pos. sensor). One silly issue seemed to cascade into confusing codes, so follow the Kiatechinfo troubleshooters and don't waste too much money replacing things unneccessarily(except maybe that IACV..).
You can drop the exhaust and use a wetvac to see if there is obvious restriction prior to blowing money on a cat. (my first cat cost $700 just for the part, no installation). Or, you may have a bunch of rust and debris clogging the second cat like Ronjohn, and be able to blow it out and still use it. Just dropping the flange after the first cat and driving it (yes noise and all), might show a huge difference.
Anyway... good luck with it. Funny how frustrating it is when troubleshooting but how it all makes sense after you're done....

 

[Kevster]

Seafoam does some almost miraculous things to dirty injectors and intakes.... Just sayin...

 

[flashover]

Ok, I am making headway. Car is running about 50% better, I can make it around the block with some throttle response, before I would have to just barely press on the throttle and the car would slowly speed up as long as i wasn't on a hill, but now, it only cuts out and sputters.
I think I need some help interpreting the results of the back pressure test. With the throttle at idle the pressure is below 1psi, at a steady 2500 rpm it stays at about 1 or <1, at about 3000-4000 the pressure is about 3-4psi until it bogs down. When that happens the pressure pops up to about 6-8 and then it immediately follows the throttle back down. If i rev the engine (vrom vrom) I can get the pressure up to about 6 at each rev. Now, should the pressure stay low no matter what I do to the throttle or is it normal for the pressure to increase with RPM.
I have checked the spark plugs and reduced the gap to .030' "they are NGK and they were gapped at about .045-.050", verified that each plug has a spark, and performed a compression test on the cylinders. The compression on all four was within 10% of 140psi.
Tomorrow I am replacing the IACV and TPS and cleaning the Mass air flow component, I have also cleaned the Throttle body. Lets see what happens.
By the way, the headlights are fixed. The HEAD LAMP relay was missing.
If I can get some help with the Back pressure results I would appreciate it. Thanks guys.

 

[ronjohn]

Did you ever try disconnecting the pipe between the two cats and going for a drive?

 

[flashover]

Did you ever try disconnecting the pipe between the two cats and going for a drive?

No I never did, I will do that tomorrow. I thought that the back-pressure test would tell me if the cat was bad, I didn't know that it would be so difficult to interpret. Also, I never mentioned this before but the exhaust sounds like it is running through an aluminum coke can. Is this another hint that the CAT is bad or is it an exhaust leak?
I cleaned the throttle body, IACV, and re-installed them, there was no improvement. The car with rev awesome in the garage and at a stop, but once its in drive and I try to accelerate, the car just has no response if I am at any kind of incline, if it is on a flat road it will slowly get moving. Ill let you know how the test drive goes.

 

[flashover]

I took off the short section of exhaust tubbing and took a look inside both catalytic converters, they are both completely empty. Someone has already cleaned them out. Does this explain anything or does it complicate things? An yes, I did drive it and it still drives like crap.

 

[ronjohn]

With both cats knocked out i wonder if your ECM is wacked out, wow! good luck with it. No other codes, or for the O2 sensors either? disconnect the battery for 10 minutes to reset the ecm Fuel trim and see if it runs ok for a little while after that. If it does, fix the cat issue if you can afford it anyonelse have a clue here Reguard's Ronjohn.

 

[Kevster]

That thing will NOT run correctly without a catalyst. Believe me I tried. I took out my old plugged one, and busted the guts out, and put her back in (I was waiting for my new one from UPS). Ran worse than it did with the plugged one! I think it jacks up the fuel mixture so bad the ECU doesn't know what to do. I am preety sure you can leave the second cat out....but replace the primary cat.
You might need to do the ol vacuum test and see if there is restriction in the muffler/tailpipe area. Chucks of leftover cat guts can get back and cause restriction in the muffler. I am a firm believer in putting a wet vac on the tailpipe and seeing if you hear a change in pitch, revealing a restriction. If the pipe is disconnected at the flange between cats, your wet vac should sound the same whether on or off the tailpipe. Just my cheapo backyard method of testing restriction....

 

[flashover]

I installed a new primary cat and reset the fuel trim. For about the first two blocks the car ran better, but then the engine light came on and the same problem came back. So I went to U Pull And Pay and got a bunch of parts. I swapped out the Mass Air Flow, TPS, Cleaned the EGR and double checked the IAC to be sure that it is operating smooth. I reset the computer again and went for a drive, no change. I pulled the codes again, they are 507 and 300-304. I also checked the TPS with and OHM meter and it increases nice and smooth with no drops. I used a stethoscope to check the injectors and they are all clicking. I even checked all grounds that I can find. Another thing I noticed is that once in a while I hear a popping in the intake manifold. Any suggestions?

 

[DavesSpectra]

I re-read the posts and I found " Both cams line up with top marks"... Had you also checked the crank position...Does/did it match it's marks also? The timing belt may have jumped a tooth. How old is the timing belt?
I'm a little bothered with the 6~8 psi on the exhaust and the cats being empty... What's causing the back pressure? did the crap from the cats get pushed into the muffler?
As ronjohn said try driving it with the short extension pulled loose and report back.
Sounds like there is still back pressure there.
What's the readings on the first and second O2 sensors? The should not be the same (or close).
Dave
Dave

 

[flashover]

Crank is at TDC and both cams are line up perfect.
I installed a new catalytic converter and took apart the exhaust all the way back to the muffler and made sure that there is no blockage.
I didnt recheck the backpressure since there is nothing to cause it now I think this higher readings were a result of a bad gauge.
Replaced the spark plugs and wires
I don't know what the two O2 sensors are reading because I do not have a scanner and I don't know any other way to test it.
I am not getting the 507 code anymore but I am still getting the 300-304 miss fire codes.
The symptoms are, sputtering when accelerating, rough idle, occasional popping in the intake, if I rev the engine when I am in park occasionally the car will idle high for about 20 seconds and then come down and sometimes die.
I am at a loss with this thing.

 

[Kevster]

Are you sure you don't have an intake manifold leak? And I might have missed it, but did you check the spark plug gaps and set them no larger than .031". Plain ol NGK cheapo plugs with a rather small gap work best with the Rio. (been down that road too). You can mail order remanufactured injectors for about $30 each online. If I were you I would get a new intake manifold gasket ($16 or so??) and take the injectors out and manifold off the head and clean it really good. Pull the throttle body and clean that really good as well. With all the miles that thing has, it is bound to be gunked up in the intake. Put it back together with the new gasket, and see if it helps. While you are back in there look closely at all the hoses and connectors to be certain they are all on and snug.
I say all this assuming you have already done compression tests, and are using fresh fuel (not an old tank that has been sitting for months or years...). My Rio only had 140K and it was really dirty all through the intake/throttle body/injectors. Seafoam works good if you don't want to disassemble and clean it the hard way.

 

[Kevster]

Okay, just went back and re-read....so you have checked compression, and gapped plugs right, so lets see about that IACV.

Cleaning mine didn't help me with my issues. I cleaned it and then cleaned it again, and then disassembled it! In the end I replaced it with a gently used one, and it floored me that the IACV could cause me so much grief! Maybe I am wrong, but after what I went through, I want to make sure you have a good IACV. And don't expect too much from that little engine...as you are at higher altitudes and they aren't even that powerful at sea level. I grew up in Gallup, and whenever I go back for a visit, I am whining about how weak my vehicles are there! Good luck!