just bought my 1st Toyota. Help with CEL

[eddo3]

1997 Avalon w/148k miles. Starts easily even below 30 deg. Runs strong and smooth while cold. After it gets up to operating temp and has been warm for a while I'll get a rough idle and surge while coasting. Initially had a P0420 and P0402. Cleared the codes and the only symptoms that returned were the rough idle and surge while coasting - leading me to look at the EGR system as culprit. The P0420 shouldn't be linked to the driveability issues as they're intermittent, is this essentially correct?

I've read most of everything posted here and elsewhere concerning the P0402 and have an EGR VSV on order from a dealer. If that doesn't do it I'm going to replace the EGR position sensor. The only other symptom I've noticed (could just be coincidental) is a smell of oil burning on exhaust just before the rough idle kicks in...

Any ideas would be appreciated. I don't have much $$$ to throw at the problem as I'm in the middle of a divorce (prompting my purchase) and don't need this to last much more than a year or so - though more is better!
Thanks!
Ed

[toyomoho]

Rough idle could be exhaust gas at idle, the EGR should be off at engine idle. No exhaust gas rerouting at idle, closed throttle, engine cold, light engine load or above 4000 RPM.

Could a stuck EGR valve, bad VSV valve (controls vacuum to turn on/off EGR valve) or valve position sensor.

Run down the VSV valve, remove the vacuum line going to the EGR or coming from the intake manifold (plug any lines to prevent leaks). This will turn off the EGR valve. Determine if the engine runs and idles better.

The AutoZone website may have some info on this system. The site has a self repair section for various year/make and model cars. If it does not list the Avalon use the same year Camry with the V6 (1MZ-FE) engine. The two models are almost the same.

Or pickup a Haynes manual (under $20) or try your local library that may have manuals.

There is a trouble code for the position sensor P1410.

With the Haynes manual service info you should be able to test the sensor with an ohm meter.

[eddo3]

Thanks!. I haven't gotten a position sensor code yet so I'm thinking more like sticking egr. After experiencing the exact same symptoms repeating over the last few days:
starts great
runs great cold
rough idle once fully warmed up
I decided to really wind out the engine a few times and get some gases flowing through the egr system. Guess what - no more rough idle! Fingers are crossed. I've got the new vsv due in on Tuesday. I may not need it. I bought a Haynes manual and will probably want to clean the egr valve. Never done it.

Is there anything that I can use to clean it in-place? Seafoam? Or am I just asking for trouble...

[mmejia]

Hmm...Well, I've seafoamed my car twice and it's been great. You could try it; it won't kill your car. Just make sure you do it right. There's quite a few instructions online on how to do it. Make sure actually drive the car when you do this. A lot of people tend to only rev the engine parked. One, that doesn't really quite get the job done since you're not really placing a load on the engine (when I drive it, a lot more blue smoke comes out). Two, to rev your engine at such high rpms with no load is asking for trouble.

[eddo3]

Problem solved. I bought a new EGR valve from autopartsgiant.com - $137 shipped - AC/Delco - had OEM part number on it. Half an hour later my drivability issues were gone. I had previously repaced the vsv with no resolution.

I found that website via amazon.com and also got a 5% off code. Free shipping. Best deal on the web for an egr valve. The customer service however, is hideous. No warm and fuzzy shipping confirmation or anything. Several phone calls to customer service to check status were frustrating at best. The part did show up within 2 weeks or so (CA to DC).

[supradude123]

rockauto.com

usu has lowest prices.. not in this case tho.