I have been experiencing a loud engine noise of late, it occurs when I apply the throttle only. I have also been getting a CEL (solid) with p1124/1126. Had it reset twice, came on a third time. I cleaned the MAF with electrical cleaner real well, but it took about 60 miles before the CEL came back. I have also noticed a drop in my RPMs from the normalish 750 down to about 500-600 (hard to really give an exact number) and when it is this low, there is a shudder and I can hear some metallic noise (like a loose fixture being rattled). All these symptoms came on at the same time. Anyone know anything, what it could be, past experiences. Any help would be advisable. I am going to do a oil/filter/air filter/spark plug service in the next few days. I also found out my MAF is covered under my 3rd party insurance and will have that done as well. TIA everyone.

 

Can you give more details on the loud engine noise? What RPM does it start at? Does it go away above a certain RPM? Does it get louder the higher the RPM goes? What does it sound like?

The rattle you're hearing at low RPM is most likely a loose heat shield and isn't a problem.