Heikki Kovalainen, CaterhamCaterham has decided it will not use the exhaust layout it tested at Mugello in this weekend's Spanish Grand Prix.

The team tested a new exhaust/floor configuration during testing at the Italian track last week, but it did not prove to be beneficial to the performance of the car. Heikki Kovalainen confirmed the team is still working to understand the layout, which will not be used in Spain.

"We had some parts that worked and some parts that didn't, I think it's fair to say," Kovalainen said. "The exhaust, for example, didn't work. We didn't get it to work as we were expecting. We didn't get any benefits from it."

The Finn said he was not surprised that the exhaust did not work right away, but he is confident Caterham will be able to get it working eventually.

"In a way it wasn't a surprise for me because I know that the exhaust is a difficult area," he said. "Last year I don't think we had as good an exhaust as the other teams, and this year it's not any easier, so I'm not surprised we didn't get it working at the first try. But I think we'll get the hang of it. We are working on it now to understand why we didn't get any benefits from it."

The team, however, will run a new rear wing that, while it did not work as expected at Mugello, Kovalainen believes may prove beneficial in Spain.

"We have a different rear wing that we will try here which didn't give a positive result in Mugello, but Mugello is a different circuit and there's a better chance it may work here. But apart from that the other updates that we had there we didn't get them working, so we need to work on them a bit more."