Scheduled a diagnostic test for next Monday! There goes $120 but I should find out what's wrong for sure instead of throwing money away.
Hi All,
I have a Mazda 2001 Protege ES 2.0L AUTO (no mods except for K&N air filter) and I started having hesitation and rough idles about a month ago. First time it happened was on highway at about 60kph, I had misfires and some hesitation (P0300 was read). Then started the rough idles at stop light (I had already changed my EGR valve back in 2005).
The CEL eventually went away only to come back a few days later (again, highway speed 70kph). Anyway, you all know how the story goes...
So I bring it to Mazda yesterday and tell them about the P0300s but they still insitented that they needed the connect it to their WDS... I'm like "Fine but it better find the real problem... esp. at 70$".
They call me up telling me I had a P0401 and that I needed to replace the EGR valve (again), but they said it's a new version that should fix the rough idle issue once and for all... I agreed but kept my old valve... (250$ /w laybor). I talked to the mechanic to see if he checked for header gasket leaks and such, he said he did...
Now, this morning at a stop light I get a really bad rough idle (even putting it in neutral and give it some gas didn't fix it...). Unfortunately, the CEL didn't come on.
I'll keep you posted on what I change/do to see if I can fix my problem.
Cheers,
Volt
You should be taking that back to the dealer and telling them to fix it at no cost. If you took it in and told them that you wanted the rough idle fixed, and they said that they did fix it, then they are obligated by law to perform the work on the car that will correct the issue. The law may vary slightly from state to state, but they basically owe you a fix for your car, either at no charge or a severely reduced one.
Got the gasket all changed out. Car definitely runs better, but gonna drop some seafoam in the tank just to help the idle a bit more.
Will update if anything changes. Hopefully gas mileage will go back up...
Drove around for a bit today, and it drove just like a dream, idled at 800rpm and everything. Until I got over 50mph. Then it started all over again. I'm gonna give in and get plug wires. lol
I changed my plugs and it didn't help. Inspect yours and check the gap before you replace them.
Do you have the factory timing belt and idler?
Hmm, good question. I might, but they don't look too bad.
At least the belt doesn't, I don't know where to look for the idler...
But that wouldn't explain the P303 would it?
ps. Plug wires, not the plugs themselves.![]()